Visualizing proteins in living cells without perturbing biological function remains a key challenge in chemical biology. A chemical approach to this problem is the synthesis of small molecule fluorophores that react specifically with a protein of interest (POI). We have developed a site-specific labelling method based on a Fluorogenic Addition Reaction (FlARe). The FlARe probe’s fluorescence is quenched until it undergoes thiol addition with a small, genetically encoded dicysteine peptide tag fused to the POI. Recent blue coumarin probes were shown to be highly selective for target proteins over other cellular thiols; however, fluorogens that can label in the red and green channels of the fluorescence microscope are more desirable for cellular imaging, as red light is lower in energy and therefore less photo-toxic. In the work presented herein, we use DFT calculations to guide the design of red-shifted, PeT-quenched BODIPY based dimaleimide fluorogens. Driven by the preliminary results of a FlARe probe (YC29) that emitted in the red channel, we attempted to prepare the hit compound through a new synthetic approach to further evaluate kinetics and in cellulo labelling. Given the time available, this compound was unable to be synthesized through an SNAr or Pd-catalyzed approach. Alternatives probes lacking the red-shifting substituent were synthesized and evaluated in vitro and in cellulo. The fluorescent enhancement and reaction kinetics of these probes were evaluated in detail, in order to determine the suitability of their application to cellular labelling. A green-BODIPY fluorogen was synthesized that exhibits suitable kinetics for labelling and a dramatic fluorescent enhancement of ~800-fold upon tagging. This probe was successfully applied to the specific, fluorescent labelling of a nuclear histone protein in cellulo.

Development of enzymatic labelling methods has been driven by the importance of studying molecular structures and interactions to comprehend cellular processes. Methyltransferases (MTases), which regulate genetic expression by transferring a methyl group from the cofactor S-adenosyl-L-methionine (SAM) to DNA, histones and various proteins, have been shown to accept SAM analogues with an alternative alkyl group on the sulfonium centre. These alkyl groups can be transferred to the substrate, and with a further reaction can be selectively functionalized. Thus, MTases together with SAM analogues have emerged as novel labelling tools. The project aims to use MTases to obtain an orthogonal system that can selectively use a SAM cofactor analogue to transfer functional chains to proteins with a specific motif. To achieve selectivity of the system, the SAM analogue cofactor was modified on the ribose ring; to obtain a new transferase activity of the system, the transferable methyl on the sulfonium centre was changed to a different substituent. SAM analogues were produced enzymatically with hMAT2A by using 3'-deoxy-ATP and methionine or ethionine. Mutants of SET8 and novel substrates were designed to have modifications at residues in the active site, within the vicinity of the ribose ring of SAM, and were assessed for selective activity with the new analogue cofactor. The results showed that the new cofactor 3'-deoxy-S-adenosyl-L-methionine (3'dSAM) was efficient in the mono-methylation of the substrate peptide RFRKVL, and that the mutant SET8 C270V exhibited over 13 fold MTase activity in presence of 3'dSAM and the RFRKVL substrate, in comparison with the activity with the WT sequence RHRKVL and the SAM cofactor. In addition, glutathione S-transferase (GST) was used as a model protein to express the motif RFRKVL, to transform it into a potential substrate for SET8. Assessment of the MTase activity of SET8, 3'dSAM and the novel GST substrate indicated mono-methylation of the substrate. Moreover, the motif showed no interference with GST native activity. Based on the observations, a new enzymatic system shows higher selectivity with a new analogue cofactor over SAM to effectively methylate proteins expressing the consensus RFRKVL. Work on substrates, enzymes and cofactors should continue to obtain a functional-chain transferase activity of the enzymatic system.

Innovative improvements in the area of Human-Computer Interaction and User Interfaces have en-abled intuitive and effective applications for a variety of problems. On the other hand, there has also been the realization that several real-world optimization problems still cannot be totally auto-mated. Very often, user interaction is necessary for refining the optimization problem, managing the computational resources available, or validating or adjusting a computer-generated solution. This thesis investigates how humans can help optimization methods to solve such difficult prob-lems. It presents an interactive framework where users play a dynamic and important role by pro-viding hints. Hints are actions that help to insert domain knowledge, to escape from local minima, to reduce the space of solutions to be explored, or to avoid ambiguity when there is more than one optimal solution. Examples of user hints are adjustments of constraints and of an objective function, focusing automatic methods on a subproblem of higher importance, and manual changes of an ex-isting solution. User hints are given in an intuitive way through a graphical interface. Visualization tools are also included in order to inform about the state of the optimization process. We apply the User Hints framework to three combinatorial optimization problems: Graph Clus-tering, Graph Drawing and Map Labeling. Prototype systems are presented and evaluated for each problem. The results of the study indicate that optimization processes can benefit from human interaction. The main goal of this thesis is to list cases where human interaction is helpful, and provide an ar-chitecture for supporting interactive optimization. Our contributions include the general User Hints framework and particular implementations of it for each optimization problem. We also present a general process, with guidelines, for applying our framework to other optimization problems.

Over the past decade, bioorthogonal chemistry has emerged as powerful tools used for tracking biomolecules within living systems. Despite the vast number of organic transformations in the literature, only select few reactions meet the stringent requirements of bioorthogonality. There is increasing demands to develop biocompatible reactions that display high specificity and exquisitely fast kinetics under physiological conditions. With the goal of increasing reaction rates as a means for reducing the concentrations of labelling reagents used for bioconjugation, we have developed metal-catalyzed and metal-free alkyne-nitrone cycloadditions as alternatives to azide-alkyne cycloadditions and demonstrate their applications for imaging cell surface proteins. The copper(I)-catalyzed alkyne-nitrone cycloaddition, also known as the Kinugasa reaction, is typically conducted with a Cu(I) catalyst in the absence of air. We have developed highly efficient micelle promoted multicomponent Kinugasa reactions in aqueous media to make the reaction faster and more efficient. Despite good product yields, the slow kinetics, limited substrate scope and competing side-reaction pathways precludes its practical applicability for biological labelling. We have designed and synthesized β-lactam alkyne probes obtained from these reactions for activity-based protein profiling of the activities of membrane proteins. Additionally, we report that alkyne tethered β-lactams serve as surface enhanced Raman spectroscopy (SERS) reporters bound to silver nanoparticles, and demonstrated that alkyne bound silver nanoparticles can be used for SERS imaging cell surface proteins. The strain-promoted alkyne-nitrone cycloaddition (SPANC) was also explored as a rapid alternative bioorthogonal reaction. We found that the reaction proceeded in high yield within aqueous media, and displayed rate enhancements that were 1-2 orders of magnitude faster than analogous reactions involving azides. The scope and kinetics of SPANC was evaluated in model reactions of various nitrones (acyclic and cyclic) with cyclooctynes, with the purpose of identifying stable nitrones that displayed intrinsically faster kinetics than azides in strain-promoted cycloadditions with cyclooctynes. Cyclic nitrones displayed good stability and exceptionally fast reactivity in these reactions. The SPANC reaction exhibited high selectivity in the presence of biological nucleophilic amino acid side chains and the presence of biological media did not adversely affect the reaction. We have utilized SPANC for highly specific labelling of proteins in vitro and for imaging ligand-receptor interactions on the surfaces of live cancer cells. The high selectivity, fast reaction rate, and aqueous compatibility of SPANC makes the reaction suitable for a variety of in vivo biological imaging applications.

A high sodium diet is a predominant risk factor for hypertension, which is in turn a major risk factor for cardiovascular disease. Canadians consume approximately twice the daily Adequate Intake of sodium, most of which comes from processed foods. Enhancing nutrition labelling for sodium in the form of front-of-package (FOP) labels may help consumers select healthier products. This experimental study examined the efficacy of 4 types of FOP nutrition labels on participant selection of low versus high sodium products. 430 adults from the Waterloo Region were randomly assigned to one of 5 experimental conditions: (1) a control condition with no FOP label; (2) a basic numeric FOP label; (3) a numeric FOP label with “high” and “low” sodium content descriptors; (4) a detailed Traffic Light (TL) label with colour coding, content descriptors and numeric information; and (5) a simple TL label that did not include numeric information. Participants were shown pairs of grocery products that varied primarily in sodium content, and asked to select a free product. Selection of the low versus high sodium product served as the primary behavioural outcome; rankings and ratings of the experimental labels were also examined. Regression models were used to determine the relative efficacy of the 4 labelling formats, as well as the socio-demographic and diet and health-related predictors of these outcomes. Results indicated that participants in the FOP conditions with “low” and “high” sodium content descriptors (conditions 3, 4 and 5) were significantly more likely to choose the low sodium product compared to the control group. The detailed TL was ranked as the most effective at helping participants select low sodium products; this label was also rated significantly higher than other formats in liking, understanding and believability. Product selection did not differ significantly across socio-demographic groups, suggesting that FOP labelling might reduce the disparity in the use and understanding of nutrition labels among groups of varying socioeconomic status. This study has important policy implications. Results suggest that FOP labels should include content descriptors, which add prescriptive value and may help consumers select healthier products by improving understanding. TL labels, which incorporate content descriptors and colour coding, are recommended for future FOP labelling initiatives.

Vor dem Hintergrund der Zunahme von Übergewicht, Adipositas und daraus resultierender gesundheitlicher Gefährdungen wie Herz-Kreislauferkrankungen und Stoffwechselerkrankungen, zum Beispiel durch mangelndes Ernährungswissen, wird seit längerem über eine einfache erweiterte Lebensmittelkennzeichnung diskutiert. Bisher sind erweiterte Kennzeichnungsmodelle auf Lebensmittelverpackungen zu finden. Eingangs wird das Modell „Kennzeichnung unter Verwendung der GDA“ dargestellt, welches der Verband der europäischen Lebensmittelindustrie (CIAA) für eine vereinfachte Nährwertkennzeichnung für verpackte Lebensmittel entwickelt hat. Die erweiterten Nährwertangaben werden mit dem Modell „1 plus 4“ als Schwerpunkt des nationalen Aktionsplans in Deutschland zur Prävention von Fehlernährung, Bewegungsmangel, Übergewicht und damit zusammenhängende Krankheiten als „Leitfaden für erweiterte Nährwertinformationen auf Lebensmittelverpackungen“ durch das Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz (BMELV) veröffentlicht. Das Modell „Ampelsystem“ wurde von der britischen Lebensmittelbehörde Food Standard Agency (FSA) entwickelt, mit dem Ziel, dem Verbraucher verständliche Informationen zu geben. Ein positiver Nebeneffekt der Ampel ist es, die Lebensmittelhersteller zu motivieren, die Inhaltsstoffe und die Zusammensetzung ihrer Produkte zu prüfen. Die Verkaufszahlen britischer Unternehmen zeigen, dass die Verbraucher ihren Lebensmitteleinkauf auf das System ausrichten. Abschließend wird das schwedische „Keyhole-Modell“ dargestellt. In diesem werden die Lebensmittel für den Verbraucher anhand der Kategorien „gesund“ oder „weniger gesund“ hervorgehoben. Die zentrale staatliche Behörde für Ernährung und Trinkwasser (NFA) führte das „grüne Schlüsselloch“ ein. Das „Keyhole-Modell“ soll zur gesunden Ernährung beitragen. Zusammenfassen lässt sich konstatieren, dass keines der dargestellten Modelle mehrheitlich akzeptiert wird. Zwar verfolgen alle Modelle das gleiche Ziel, die Sensibilisierung der Verbraucher als Hilfestellung für die Auswahl gesunder Lebensmittel, aber die Ansätze der Modelle sind verschiedenartig. Die Entscheidung für ein europäisches einheitliches Modell steht noch aus. / Regarding the increase of overweight, obesity and resultant health hazards such as cardiovascular diseases and metabolic diseases, for example by lack of nutrition knowledge, simple advanced food labelling has been discussed for some time. So far, advanced identification models can be found on food packaging. At first, the model identification using the GDA is shown, which has been developed by the Association of European food industry (CIAA) for a simplified nutrition labelling for packaged foods. The expanded nutrition information are published with "one plus four" model as the focus of the national plan of action in Germany on the prevention of malnutrition, physical inactivity, obesity and related diseases as a "Guide for expanded nutrition information on food packaging" by the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV). The "traffic light system“ model has been developed by the British Food Administration Food Standard Agency (FSA) to give consumers clear information. A positive side effect of the traffic light system is to motivate food manufacturers to check the ingredients and the composition of their products. The sales of British companies show that consumers adjust their food shopping to the system. Finally, the Swedish "keyhole" model is shown. In this, the food is categorised for the consumer as "healthy" or "less healthy". The central government agency for food and drinking water (NFA) introduced the "green keyhole”. The "keyhole” model is to contribute to a healthy nutrition. Summarizing it can be stated that none of the models presented is accepted by majority. Although all the models follow the same objective, the promotion of consumer awareness as an aid for the selection of healthy food, but the approaches of the different models are different. The decision for a European standard model is still pending.

Motivation There is international agreement and recognition that the health status of the worlds' population is a cause for concern and that one of the key risk factors for many of the diseases that are increasing at an alarming rate (heart disease, diabetes, cancer) in both developed and developing countries, is diet. Despite many successes (especially in the areas of the eradication and containment of infectious disease and reduced fertility) and the huge advances in scientific research and technology, that have increased both what is known, and what can be done, for prevention and risk management, we still face what many describe as a crisis. Knowledge it seems is not always adequately reflected in public health practice. The objective of the local (Department of Health, Directorate of Food Control) and international (WHO, Codex Alimentarius) drive towards increased and improved food labelling, is that if consumers have reliable nutrition information available at the point of purchase and if they understand how their diet affects their risk of diseases, they will be able to make risk-reducing food choices. This could ultimately have a significant positive public health impact. The food industry has also expressed an interest through the concept of functional foods (food similar in appearance to conventional food that is intended to be consumed as part of a normal diet, but has been modified to subserve physiological roles beyond the provision of simple nutrient requirements), that albeit in reality financially motivated, could provide consumers with the opportunity to reduce their risks of some diseases through readily available, good-tasting diets rather than through the use of curative measures only. For the success of both these initiatives in public health terms, consumers must: o accept the link between the food that they eat and their health o actively look for and trust the messages communicated be able to correctly process and integrate the information o make a purchasing decision. This highlights the importance of in-depth consumer understanding in order to ensure that regulatory, educational and marketing strategies will affect positive behaviour change and improve health status. Little consumer research has been done in South Africa to assist all those involved (government, industry, researchers, nutrition experts I dietitians, educators) in gaining potentially important insights. Objectives Of South Africa's almost 31 million adults, some 11 million live in the metropolitan areas and so have relative exposure to most media and access to the widest range of available food products. This group is also a microcosm of the larger South Africa - being made up of all races, ages and living standards. The overall objective of this study was to investigate the beliefs and practices of South African metropolitan adults, in relation to the food and health link and the health information contained on food packages in order to consider the implications for functional foods. The study design was focussed on four key variables, namely, gender, race, age and living standard measure (LSM). Methods The study was designed to ensure that the results would be representative of the metropolitan adult (>I6 years) population and that they could be weighted and extrapolated. 2000 adults made up of 1000 Blacks. 640 Whites, 240 Coloureds and 120 Indians, with a 50150 gender split were drawn using a stratified, random (probability) sampling method in order to allow for the legitimate use of the mathematics of probability as well as to avoid interviewer bias. The study group were interviewed, face-to-face, in home, in the preferred language from English, Afrikaans, Xhosa, Zulu, Tswana, North Sotho and South Sotho, by trained field workers. A minimum 20% back-check on each interviewer's work was undertaken to ensure reliability and validity of the data. The field worker used a pre-coded questionnaire that included seventeen food related questions designed by a multidisciplinary team of marketers, dietitians, nutritionists and research specialists. The food questions used a 5-point Likert scale in order to measure attitude. The data was captured (3 questionnaire were excluded due to being incorrectly filled in) and the computer software package STATISTICA@ Release 6, which was used to perform the statistical analysis. The data was data was weighted to represent the total metropolitan population prior to analysis. Quantitative data was statistically analysed in order to generate relevant descriptive statistics, cross tabulations and statistical tests. Results The study considered four variables; gender, race (Black, White, Coloured, Indian), age (16-29, 30-44,45+) and living standards measure (LSM 2-3, LSM 4-6, LSM 7-10), to explored four statements: 1. I believe food can have an effect on my health 2. 1 always look for health information contained on the packaging of food products 3. 1 don't take any notice of health information as it is only marketing hype 4. 1 buy food that claims to contribute to my health. The overall response to the belief that food can have an effect on health was positive (54%). There was no practical significant difference between age groups and genders but there were practical significant differences between Blacks and the other race groups (Blacks having the lowest belief in the food and health link) and between the highest LSM group and the other LSM groups (LSM 7-1 0 had the strongest belief in the link between food and health and this belief decreased with decreasing LSM). Forty-two percent of respondents always look for health information on the packaging of food, but there was no practical significant difference between all the variables, however women were more likely than men to always look for health information on food packaging. Over half the respondents (51%) stated that they look for health information and that it is not only marketing hype. There was a small practical significant difference between the top and the bottom LSM group with LSM 7-10 being less sceptical about the health information on food packaging. 67% buy foods that claim to beneffi their health and there was a small practical significant difference between Blacks and Whites, with more Blacks agreeing that they buy foods that claim to contribute to health. CONCLUSION Findings from this study indicate that adult metropolitan South Africans label reading practices are influenced by a number of factors including attitudes, beliefs and practices and that there are differences based on gender, race, age and LSM which must be considered by regulators in drafting food labelling regulations; the food industry when considering and developing functional foods; and nutrition experts when planning education strategies. Whilst the labelling of foods with health information and the development of function foods might indeed potentially empower consumers to effectively reduce their risk of many chronic diseases, on its own it is not enough. Nutrition education is vital and must be planned giving due consideration to the differences in belief and practices that exist within the different gender, race, age and LSM groups found in South Africa. Food consumption patterns are influenced by consumer attitudes, beliefs, needs, lifestyles and social trends and so more multi-disciplinary research in these fields must be encouraged to find ways to improve nutritional intakes that will lead to improved health for all South Africans. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2005.

Eco-labels are increasingly important to certify food that is produced under sustainable conditions. In this paper variables are analysed that are important for consumers’ purchase decisions of eco-labelled food exemplified by the case of Fairtrade products. The focus lies on the distinction between people’s subjective (perceived) knowledge and objective knowledge (actual) about the Fairtrade label. The empirical data for the study was gathered by a survey, which involved a quota sampling of 203 people in Berlin. The results justify the distinction between subjective and objective knowledge. Subjective knowledge proved to be a strong predictor for both attitude and consumption towards the label, whereas objective knowledge did not show a significant influence. Further, attitude in general was confirmed to be a predictor for the consumption of Fairtrade products.

Motivation There is international agreement and recognition that the health status of the worlds' population is a cause for concern and that one of the key risk factors for many of the diseases that are increasing at an alarming rate (heart disease, diabetes, cancer) in both developed and developing countries, is diet. Despite many successes (especially in the areas of the eradication and containment of infectious disease and reduced fertility) and the huge advances in scientific research and technology, that have increased both what is known, and what can be done, for prevention and risk management, we still face what many describe as a crisis. Knowledge it seems is not always adequately reflected in public health practice. The objective of the local (Department of Health, Directorate of Food Control) and international (WHO, Codex Alimentarius) drive towards increased and improved food labelling, is that if consumers have reliable nutrition information available at the point of purchase and if they understand how their diet affects their risk of diseases, they will be able to make risk-reducing food choices. This could ultimately have a significant positive public health impact. The food industry has also expressed an interest through the concept of functional foods (food similar in appearance to conventional food that is intended to be consumed as part of a normal diet, but has been modified to subserve physiological roles beyond the provision of simple nutrient requirements), that albeit in reality financially motivated, could provide consumers with the opportunity to reduce their risks of some diseases through readily available, good-tasting diets rather than through the use of curative measures only. For the success of both these initiatives in public health terms, consumers must: o accept the link between the food that they eat and their health o actively look for and trust the messages communicated be able to correctly process and integrate the information o make a purchasing decision. This highlights the importance of in-depth consumer understanding in order to ensure that regulatory, educational and marketing strategies will affect positive behaviour change and improve health status. Little consumer research has been done in South Africa to assist all those involved (government, industry, researchers, nutrition experts I dietitians, educators) in gaining potentially important insights. Objectives Of South Africa's almost 31 million adults, some 11 million live in the metropolitan areas and so have relative exposure to most media and access to the widest range of available food products. This group is also a microcosm of the larger South Africa - being made up of all races, ages and living standards. The overall objective of this study was to investigate the beliefs and practices of South African metropolitan adults, in relation to the food and health link and the health information contained on food packages in order to consider the implications for functional foods. The study design was focussed on four key variables, namely, gender, race, age and living standard measure (LSM). Methods The study was designed to ensure that the results would be representative of the metropolitan adult (>I6 years) population and that they could be weighted and extrapolated. 2000 adults made up of 1000 Blacks. 640 Whites, 240 Coloureds and 120 Indians, with a 50150 gender split were drawn using a stratified, random (probability) sampling method in order to allow for the legitimate use of the mathematics of probability as well as to avoid interviewer bias. The study group were interviewed, face-to-face, in home, in the preferred language from English, Afrikaans, Xhosa, Zulu, Tswana, North Sotho and South Sotho, by trained field workers. A minimum 20% back-check on each interviewer's work was undertaken to ensure reliability and validity of the data. The field worker used a pre-coded questionnaire that included seventeen food related questions designed by a multidisciplinary team of marketers, dietitians, nutritionists and research specialists. The food questions used a 5-point Likert scale in order to measure attitude. The data was captured (3 questionnaire were excluded due to being incorrectly filled in) and the computer software package STATISTICA@ Release 6, which was used to perform the statistical analysis. The data was data was weighted to represent the total metropolitan population prior to analysis. Quantitative data was statistically analysed in order to generate relevant descriptive statistics, cross tabulations and statistical tests. Results The study considered four variables; gender, race (Black, White, Coloured, Indian), age (16-29, 30-44,45+) and living standards measure (LSM 2-3, LSM 4-6, LSM 7-10), to explored four statements: 1. I believe food can have an effect on my health 2. 1 always look for health information contained on the packaging of food products 3. 1 don't take any notice of health information as it is only marketing hype 4. 1 buy food that claims to contribute to my health. The overall response to the belief that food can have an effect on health was positive (54%). There was no practical significant difference between age groups and genders but there were practical significant differences between Blacks and the other race groups (Blacks having the lowest belief in the food and health link) and between the highest LSM group and the other LSM groups (LSM 7-1 0 had the strongest belief in the link between food and health and this belief decreased with decreasing LSM). Forty-two percent of respondents always look for health information on the packaging of food, but there was no practical significant difference between all the variables, however women were more likely than men to always look for health information on food packaging. Over half the respondents (51%) stated that they look for health information and that it is not only marketing hype. There was a small practical significant difference between the top and the bottom LSM group with LSM 7-10 being less sceptical about the health information on food packaging. 67% buy foods that claim to beneffi their health and there was a small practical significant difference between Blacks and Whites, with more Blacks agreeing that they buy foods that claim to contribute to health. CONCLUSION Findings from this study indicate that adult metropolitan South Africans label reading practices are influenced by a number of factors including attitudes, beliefs and practices and that there are differences based on gender, race, age and LSM which must be considered by regulators in drafting food labelling regulations; the food industry when considering and developing functional foods; and nutrition experts when planning education strategies. Whilst the labelling of foods with health information and the development of function foods might indeed potentially empower consumers to effectively reduce their risk of many chronic diseases, on its own it is not enough. Nutrition education is vital and must be planned giving due consideration to the differences in belief and practices that exist within the different gender, race, age and LSM groups found in South Africa. Food consumption patterns are influenced by consumer attitudes, beliefs, needs, lifestyles and social trends and so more multi-disciplinary research in these fields must be encouraged to find ways to improve nutritional intakes that will lead to improved health for all South Africans. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2005.

Over the past decade, bioorthogonal chemistry has emerged as powerful tools used for tracking biomolecules within living systems. Despite the vast number of organic transformations in the literature, only select few reactions meet the stringent requirements of bioorthogonality. There is increasing demands to develop biocompatible reactions that display high specificity and exquisitely fast kinetics under physiological conditions. With the goal of increasing reaction rates as a means for reducing the concentrations of labelling reagents used for bioconjugation, we have developed metal-catalyzed and metal-free alkyne-nitrone cycloadditions as alternatives to azide-alkyne cycloadditions and demonstrate their applications for imaging cell surface proteins. The copper(I)-catalyzed alkyne-nitrone cycloaddition, also known as the Kinugasa reaction, is typically conducted with a Cu(I) catalyst in the absence of air. We have developed highly efficient micelle promoted multicomponent Kinugasa reactions in aqueous media to make the reaction faster and more efficient. Despite good product yields, the slow kinetics, limited substrate scope and competing side-reaction pathways precludes its practical applicability for biological labelling. We have designed and synthesized β-lactam alkyne probes obtained from these reactions for activity-based protein profiling of the activities of membrane proteins. Additionally, we report that alkyne tethered β-lactams serve as surface enhanced Raman spectroscopy (SERS) reporters bound to silver nanoparticles, and demonstrated that alkyne bound silver nanoparticles can be used for SERS imaging cell surface proteins. The strain-promoted alkyne-nitrone cycloaddition (SPANC) was also explored as a rapid alternative bioorthogonal reaction. We found that the reaction proceeded in high yield within aqueous media, and displayed rate enhancements that were 1-2 orders of magnitude faster than analogous reactions involving azides. The scope and kinetics of SPANC was evaluated in model reactions of various nitrones (acyclic and cyclic) with cyclooctynes, with the purpose of identifying stable nitrones that displayed intrinsically faster kinetics than azides in strain-promoted cycloadditions with cyclooctynes. Cyclic nitrones displayed good stability and exceptionally fast reactivity in these reactions. The SPANC reaction exhibited high selectivity in the presence of biological nucleophilic amino acid side chains and the presence of biological media did not adversely affect the reaction. We have utilized SPANC for highly specific labelling of proteins in vitro and for imaging ligand-receptor interactions on the surfaces of live cancer cells. The high selectivity, fast reaction rate, and aqueous compatibility of SPANC makes the reaction suitable for a variety of in vivo biological imaging applications.