Introduction/purpose: Recovery from muscle damage involves a type of programmed cell death known as apoptosis. Damage Associated Molecular Patterns (DAMPs) are released after muscle damage and may cause premature apoptosis in monocytes infiltrating the damaged site. This may alter the time course of events towards recovery. Therefore, the purpose of this study was to investigate if downhill running causes a change in the susceptibility of monocytes to apoptosis. Methods: Participants (5 male, 6 female) completed a downhill running protocol consisting of 6-5 minute bouts at a speed of 6-9mph on a -15% grade treadmill. Venous blood samples were collected immediately pre-exercise (PRE), in addition to 4 -h, 24 -h and 48 -h post-exercise. Creatine kinase (CK) was measured to give an indication of muscle damage. Monocytes were analyzed by flow cytometry for expression of multicaspase and annexin v reagent was used to detect changes in the plasma membrane. A MILLIPLEX MAP human early apoptosis magnetic bead 7-plex kit (EMD Millipore, Billerica, MA) was used to assess the relative concentration of phosphorylated protein kinase B (Akt), Bcl-2 associated death promoter (BAD), B cell lymphoma-2 (Bcl-2), active caspase-8, active caspase-9, c jun N terminal kinase (JNK) and tumor protein p53 by Luminex multiplex assay. Results: CK peaked at 24- h. Monocytes showed greater expression of multicaspase at 24 –h and 48 -h than at PRE. Bcl-2, p53 and caspase-8 were all significantly greater at 24 –h than at PRE. Conclusion: Downhill running did alter the apoptotic response of monocytes and therefore may be important in the recovery process from muscle damage.

No description available.

This dissertation develops technology for microfluidic point-of-care immunoassay devices. This research (2004–2007) improved microfluidic immunoassay performance by reducing reagent consumption, decreasing analysis time, increasing sensitivity, and integrating processes using a lab-on-a-chip. Estimates show that typical hospital laboratories can save $1.0 million per year by using microfluidic chips. Our first objective was to enhance mixing in a microfluidic channel, which had been one of the main barriers to using these devices. Another goal of our studies was to simplify immunoassays by eliminating surfactants. Manufacturers of latex immunoassays add surfactants to prevent non-specific aggregation of microspheres. However, these same surfactants can cause false positives (and negatives) during diagnostic testing. This work, published in Appendix A (© 2006 Elsevier) shows that highly carboxylated polystyrene (HCPS) microspheres can replace surfactants and induce rapid mixing via diffusion in microfluidic devices. Our second objective was to develop a microfluidic device using fiber optics to detect static light scattering (SLS) of microspheres in Appendix B (© 2007 Elsevier). Fiber optics were used to deliver light emitting diode (LED) or laser light. A miniature spectrometer was used to measure 45° forward light scattering collected by optical fiber. Latex microspheres coated with PR3 proteins were used to test for the vasculitis marker, anti-PR3. No false negatives or positives were observed. A limit of detection (LOD) of 50 ng mL⁻¹ was demonstrated. This optical detection system works without fluorescence or chemiluminescence markers. It is cost effective, small, and re-usable with simple rinsing. The final objective in this dissertation, published in Appendix C (© 2007 Elsevier), developed a multiplex immunoassay. A lab-on-a-chip was used to detect multiple antibodies using microsphere light scattering and quantum dot (QD) emission. We conjugated QDs onto microspheres and named this configuration “nano-on-micro” or “NOM”. Upon radiation with UV light, strong light scattering is observed. Since QDs also provide fluorescent emission, we are able to use increased light scattering for detecting antigen-antibody reactions, and decreased QD emission to identify which antibody is present.

Syftet med projektet var att utveckla en multiplexanalys för att detektera antigen från SARS-CoV-2, influensa och respiratoriskt syncytial virus genom att använda en masspektrometrisk metod som involverar antigenspecifika bindare. Bindarna klonades, renades och biotinylerades innan de användes i en analys utvecklad genom en målinriktad metod som involverade antigenerna. En slutsats som drog var att det var möjligt för Avi-märkta bindare att specifikt binda antigen-härledda peptidmål i multiplexanalysen. / The purpose of project was to develop a multiplex assay capable of detecting antigens from SARSCoV-2, influenza and respiratory syncytial virus by utilizing a mass spectrometric approach involving antigen-specific binders. Binders were cloned, purified and biotinylated before being employed in an assay developed by though a targeted method involving the antigens. It was concluded to be possible for Avi-tagged binders to specifically bind antigen-derived peptide targets in the multiplex assay.

Infecção congênita é aquela transmitida da mãe ao feto antes do nascimento. A transmissão vertical pode ocorrer por via transplacentária ou por contato direto com o patógeno durante o parto. A fonte de infecção é o microrganismo presente no sangue da gestante durante a infecção primária ou crônica. Estima-se que as infecções perinatais representam 2% a 3% de todas anomalias congênitas e as mais comuns são representadas pela sigla TORCH, que inclui Toxoplasmose, Outras (como sífilis e varicela-zoster), Rubeóla, Citomegalovírus e Herpes. A maioria das infecções TORCH causa morbidade materna leve, assintomática, mas tem consequências fetais graves e, em geral, o tratamento da infecção materna não tem impacto sobre o resultado fetal. Por isso, o reconhecimento do contágio materno e o monitoramento fetal são de extrema importância na prevenção de doenças congênitas. O presente projeto visa o desenvolvimento de um produto multiparamétrico utilizando a tecnologia xMAP®, criada pela companhia norte-americana Luminex Corporation, para detecção simultânea de anticorpos da classe IgG anti-Toxoplasmose, anti-Rubéola e anti- Citomegalovírus em amostras de sangue coletado em papel de filtro. O produto, inédito no mercado nacional, tem o objetivo de atender à demanda específica da triagem pré-natal no país. Como objetivos específicos pode-se citar: a melhoria da eficiência dos programas de triagem pré-natal, graças à economia de tempo, amostras e reagentes; a contribuição financeira para o Brasil, uma vez que será produzido nacionalmente, gerando emprego e renda; a possibilidade de ampliar o mercado a partir do desenvolvimento futuro de novos produtos baseados na mesma metodologia. Para tanto, utilizaram-se antígenos específicos acoplados à microesferas de poliestireno e anticorpos de detecção conjugados à estreptavidina-ficoeritrina. Foram analisadas 1499 amostras de gestantes, coletadas em papel de filtro, cedidas e previamente triadas pela APAE-Goiânia, com o objetivo de comparar os resultados obtidos através da análise com o protótipo desenvolvido com aqueles já confirmados pelo laboratório utilizando a tradicional metodologia de ELISA. Os resultados de Concordância e Sensibilidade foram superiores a 78% para todos os parâmetros. Por outro lado, os valores de Especificidade foram mais baixos, principalmente para os parâmetros Rubéola e Citomegalovírus. Importante ressaltar o pequeno número de amostras com resultado negativo para Citomegalovírus e Rubéola disponível, o que refletiu diretamente no cálculo da Especificidade do produto / Congenital infections are transmitted from the mother to the fetus before birth. Vertical transmission can occur via placenta or by direct contact with the pathogen during childbirth. The source of infection is the microorganism present in the pregnant woman\'s blood during primary or chronic infection. It is estimated that perinatal infections are responsible for 2% to 3% of all congenital abnormalities and the most common are represented by the acronym TORCH, including Toxoplasmosis, Others (such as syphilis and varicella-zoster), Rubella, Cytomegalovirus (CMV) and Herpes. Most infections TORCH causes mild maternal morbidity, asymptomatic, but has serious fetal consequences fetal and, generally, maternal infection treatment has no impact on fetal outcome. Therefore, the recognition of maternal infection and fetal monitoring are extremely important in preventing birth defects. This project aims to develop a product using the multiplex xMAP® technology, created by US company Luminex Corporation, for simultaneous detection of IgG antibodies anti-toxoplasmosis, antirubella and anti-cytomegalovirus in blood samples collected in filter paper. The product, unprecedented in brazilian market, aims to meet the specific demand of prenatal screening in Brazil. The specific objectives are: improving the efficiency of prenatal screening programs, thanks to savings in time, samples and reagents; the financial contribution for Brazil, as it will be produced nationally, generating jobs and income; the possibility of expanding the market from the future development of new products based on the same methodology. For this purpose, were used specific antigens coupled to polystyrene beads and antibodies conjugated to streptavidin-phycoerythrin. Were analyzed 1499 samples of pregnant women, collected on filter paper, pre-screened by APAE-Goiânia, in order to compare the results obtained from the analysis with the prototype developed with those already confirmed by the laboratory using traditional ELISA methodology. The results of Concordance and Sensitivity were higher than 78% for all parameters. In contrast, the Specificity values were lower, especially for Rubella and Cytomegalovirus parameters. Importantly the small number of negative samples negative for Cytomegalovirus and Rubella provided by APAE-Goiânia, which is directly reflected in the product specificity value.

Infecção congênita é aquela transmitida da mãe ao feto antes do nascimento. A transmissão vertical pode ocorrer por via transplacentária ou por contato direto com o patógeno durante o parto. A fonte de infecção é o microrganismo presente no sangue da gestante durante a infecção primária ou crônica. Estima-se que as infecções perinatais representam 2% a 3% de todas anomalias congênitas e as mais comuns são representadas pela sigla TORCH, que inclui Toxoplasmose, Outras (como sífilis e varicela-zoster), Rubeóla, Citomegalovírus e Herpes. A maioria das infecções TORCH causa morbidade materna leve, assintomática, mas tem consequências fetais graves e, em geral, o tratamento da infecção materna não tem impacto sobre o resultado fetal. Por isso, o reconhecimento do contágio materno e o monitoramento fetal são de extrema importância na prevenção de doenças congênitas. O presente projeto visa o desenvolvimento de um produto multiparamétrico utilizando a tecnologia xMAP®, criada pela companhia norte-americana Luminex Corporation, para detecção simultânea de anticorpos da classe IgG anti-Toxoplasmose, anti-Rubéola e anti- Citomegalovírus em amostras de sangue coletado em papel de filtro. O produto, inédito no mercado nacional, tem o objetivo de atender à demanda específica da triagem pré-natal no país. Como objetivos específicos pode-se citar: a melhoria da eficiência dos programas de triagem pré-natal, graças à economia de tempo, amostras e reagentes; a contribuição financeira para o Brasil, uma vez que será produzido nacionalmente, gerando emprego e renda; a possibilidade de ampliar o mercado a partir do desenvolvimento futuro de novos produtos baseados na mesma metodologia. Para tanto, utilizaram-se antígenos específicos acoplados à microesferas de poliestireno e anticorpos de detecção conjugados à estreptavidina-ficoeritrina. Foram analisadas 1499 amostras de gestantes, coletadas em papel de filtro, cedidas e previamente triadas pela APAE-Goiânia, com o objetivo de comparar os resultados obtidos através da análise com o protótipo desenvolvido com aqueles já confirmados pelo laboratório utilizando a tradicional metodologia de ELISA. Os resultados de Concordância e Sensibilidade foram superiores a 78% para todos os parâmetros. Por outro lado, os valores de Especificidade foram mais baixos, principalmente para os parâmetros Rubéola e Citomegalovírus. Importante ressaltar o pequeno número de amostras com resultado negativo para Citomegalovírus e Rubéola disponível, o que refletiu diretamente no cálculo da Especificidade do produto / Congenital infections are transmitted from the mother to the fetus before birth. Vertical transmission can occur via placenta or by direct contact with the pathogen during childbirth. The source of infection is the microorganism present in the pregnant woman\'s blood during primary or chronic infection. It is estimated that perinatal infections are responsible for 2% to 3% of all congenital abnormalities and the most common are represented by the acronym TORCH, including Toxoplasmosis, Others (such as syphilis and varicella-zoster), Rubella, Cytomegalovirus (CMV) and Herpes. Most infections TORCH causes mild maternal morbidity, asymptomatic, but has serious fetal consequences fetal and, generally, maternal infection treatment has no impact on fetal outcome. Therefore, the recognition of maternal infection and fetal monitoring are extremely important in preventing birth defects. This project aims to develop a product using the multiplex xMAP® technology, created by US company Luminex Corporation, for simultaneous detection of IgG antibodies anti-toxoplasmosis, antirubella and anti-cytomegalovirus in blood samples collected in filter paper. The product, unprecedented in brazilian market, aims to meet the specific demand of prenatal screening in Brazil. The specific objectives are: improving the efficiency of prenatal screening programs, thanks to savings in time, samples and reagents; the financial contribution for Brazil, as it will be produced nationally, generating jobs and income; the possibility of expanding the market from the future development of new products based on the same methodology. For this purpose, were used specific antigens coupled to polystyrene beads and antibodies conjugated to streptavidin-phycoerythrin. Were analyzed 1499 samples of pregnant women, collected on filter paper, pre-screened by APAE-Goiânia, in order to compare the results obtained from the analysis with the prototype developed with those already confirmed by the laboratory using traditional ELISA methodology. The results of Concordance and Sensitivity were higher than 78% for all parameters. In contrast, the Specificity values were lower, especially for Rubella and Cytomegalovirus parameters. Importantly the small number of negative samples negative for Cytomegalovirus and Rubella provided by APAE-Goiânia, which is directly reflected in the product specificity value.

<p>  </p> <p>Designing and developing a diagnostic technology that is capable of highly sensitive and specific, multiplexed, high-throughput, and quantitative biomarker assays for disease diagnosis and progression is of the upmost importance in modern medicine and patient care. Current diagnostic assays capable of multiplexed and high-throughput analysis include mass spectrometry, electrochemistry, polymerase chain reaction (PCR), and fluorescence-based techniques, however, these techniques suffer from a lack in sensitivity, false responses, or extensive sample processing that are detrimental to clinical diagnostics. To overcome these sensitivity challenges, the field of nanoplasmonics has become utilized when developing diagnostic assays. Plasmonic-based diagnostic tests utilize the unique optical, chemical, and physical property of nanoparticles to increase the sensitivity of the assay. In this dissertation, novel diagnostic platforms that utilize nanoparticles and their localized surface plasmon resonance (LSPR) property will be introduced. LSPR is an optical property in noble metallic nanoparticles that is referred to as the collective oscillation of free electrons upon light irradiation. It is highly dependent on the shape, size, and dielectric constant (refractive index) of the surrounding medium of the nanoparticle and LSPR sensing is based on a change in these properties. In this dissertation, the LSPR property is utilized to fabricate nanoplasmonic-based diagnostic platforms that are capable of multiplexed and high-throughput biomarker assays, with high sensitivity and specificity. The work presented in this dissertation is presented as six chapters, (1) Introduction. (2) Methods, (3) Fabrication of a LSPR-based multiplexed and high-throughput biosensor platform and its application in performing microRNA assays for the diagnosis of bladder cancer. In this chapter, the advancement of single-plex solid state LSPR-based biosensors into a multiplexed and high-throughput diagnostic biosensor platform is reported for the first time. The diagnostic biosensor platform is first fabricated utilizing different gold nanoparticles (spherical nanoparticles, nanorods, and triangular nanoprisms), and then with the gold triangular nanoprisms as the nanoparticle of choice, microRNA assays were performed. The developed biosensor platform is capable of assaying five different types of microRNAs simultaneously at an attomolar limit of detection. Additionally, five microRNA were assayed in 20-bladder cancer patient plasma samples. (4) Development/optimization of the biosensor platform presented in Chapter 3 for the detection of COVID-19 biomarkers. In this chapter, the biosensor platform utilized in Chapter 3 was designed to assay 10 different COVID-19 specific biomarkers from three classes (six viral nucleic acid gene sequences, two spike protein subunits, and two antibodies) with limit of detections in the attomolar range and with high specificity. The high-throughput capability of the biosensor platform was advanced, with the platform performing analysis of a single biomarker in 92 patient samples simultaneously. Additionally, the biomarker platform was utilized to assay all 10 biomarkers in a total of 80 COVID-19 patient samples.  (5) Further optimization of the biosensor platform for the development of a highly specific antibody detection test for COVID-19. During the COVID-19 pandemic, knowledge was gained on the specificity of antibodies produced against COVID-19. In this chapter, that knowledge was applied towards the optimization of the biosensor platform presented in Chapter 4 in order to assay SARS-CoV-2 neutralizing antibody IgG. The optimization of the biosensor platform included the size of the gold triangular nanoprisms and the receptor molecule of choice. The biosensor platform assayed this highly specific COVID-19 IgG antibody with a limit of detection as low as 30.0 attomolar with high specificity and no cross reactivity. Additionally, as a proof of concept, the biosensor platform was utilized in a high-throughput format to assay SARS-CoV-2 IgG in a large cohort of 121 COVID-19 patient samples simultaneously. (6) Advancement of the biosensor platform from a 96-well plate to a 384-well plate and its application in assaying microRNA for early diagnosis of pancreatic cancer. In this chapter, the high-throughput capabilities of the biosensor platform presented in Chapters 3-5 was expanded by increasing the sensor amount in one platform from 92 to 359. The 384-well plate biosensor platform was designed, optimized, and utilized to perform microRNA assays for early-stage pancreatic cancer diagnosis. The optimization of the biosensor platform included the manipulation of LSPR-based parameters and the -ssDNA receptor molecule in order to obtain low limit of detections (high sensitivity). Additionally, the biosensor platform assayed two microRNA in a large cohort (n=110) of pancreatic cancer and chronic pancreatitis patient samples. </p>

Sunflower (Helianthus annuus L.) high oleic acid content lines differ from conventional sunflower by an increase in oleic acid (C18:1) content of more than 60%. The current sunflower cultivars under production in South Africa are standard sunflower with high levels of linoleic acid (C18:2). The aim of this study was to improve the quality of oil produced by local sunflower germplasm with respect to oleic acid through employing a marker-assisted breeding technique to facilitate and speed up the recovery of the high oleic acid allele into the background of the recurrent parent genome. Eleven sunflower breeding genotypes with high and low oleic acid traits were obtained from the Agricultural Research Council-Grain Crops Institute (ARC-GCI) in Potchefstroom. The breeding genotypes were phenotypically characterised based on their oleic and linoleic acid levels using gas chromatography. Results demonstrated that the average mean of oleic and linoleic acid contents in high oleic acid genotypes were 72% and 17% respectively, while the average mean of oleic acid and linoleic acid contents in wild type lines were 33.5 % and 54 % respectively. These results indicated a perfect negative correlation between the amount of oleic and linoleic acids possessed in high and low oleic acid genotypes (R2 = -99.16%). Sequence characterised amplified region (SCAR) markers were tested to ascertain if any of the ten available dominant FAD2-1 markers was segregating with the high oleic acid allele. Four dominant SCAR markers (FAD2-1F4/R1; FAD2-1F4/R2; FAD2-1F13/R1; FAD2-1F14/R2) were strongly associated with the high oleic acid trait (P< 0.001). With regard to the inheritance of the high oleic acid trait, 143 plants of the F2 segregating population derived from a cross between the high oleic acid parent (AP901-95-3-4-1) and low oleic acid parent (H55-9-2-1-1) were genotyped with the four SCAR markers to determine the genetic state concerning the high oleic acid gene (Ol). Results from a Chi square analysis of the observed frequencies of each dominant FAD2-1 marker locus in 143 F2 individuals indicated that the deviation from the expected ratio of 3:1 (high to low oleic acid) was not statistically significant (P< 0.95) from the observed segregation ratio. These results were consistent with the previous finding that an incomplete dominant gene governs sunflower high oleic acid. A multiplex assay of 78 Simple sequence repeat (SSR) markers was optimised and evaluated on 143 plants of the F2 population to determine suitable SSR markers that can be used in a marker-assisted background selection. Only 14 markers were suitable for marker-assisted background selection based on their high polymorphic information content, allele frequency and maximum allele numbers. In conclusion, this study demonstrated the potential of using SSR and SCAR marker systems as a breeding tool to characterise and speed up the selection process in marker-assisted backcross breeding. / Thesis (MSc (Botany))--North-West University, Potchefstroom Campus, 2013.

Sunflower (Helianthus annuus L.) high oleic acid content lines differ from conventional sunflower by an increase in oleic acid (C18:1) content of more than 60%. The current sunflower cultivars under production in South Africa are standard sunflower with high levels of linoleic acid (C18:2). The aim of this study was to improve the quality of oil produced by local sunflower germplasm with respect to oleic acid through employing a marker-assisted breeding technique to facilitate and speed up the recovery of the high oleic acid allele into the background of the recurrent parent genome. Eleven sunflower breeding genotypes with high and low oleic acid traits were obtained from the Agricultural Research Council-Grain Crops Institute (ARC-GCI) in Potchefstroom. The breeding genotypes were phenotypically characterised based on their oleic and linoleic acid levels using gas chromatography. Results demonstrated that the average mean of oleic and linoleic acid contents in high oleic acid genotypes were 72% and 17% respectively, while the average mean of oleic acid and linoleic acid contents in wild type lines were 33.5 % and 54 % respectively. These results indicated a perfect negative correlation between the amount of oleic and linoleic acids possessed in high and low oleic acid genotypes (R2 = -99.16%). Sequence characterised amplified region (SCAR) markers were tested to ascertain if any of the ten available dominant FAD2-1 markers was segregating with the high oleic acid allele. Four dominant SCAR markers (FAD2-1F4/R1; FAD2-1F4/R2; FAD2-1F13/R1; FAD2-1F14/R2) were strongly associated with the high oleic acid trait (P< 0.001). With regard to the inheritance of the high oleic acid trait, 143 plants of the F2 segregating population derived from a cross between the high oleic acid parent (AP901-95-3-4-1) and low oleic acid parent (H55-9-2-1-1) were genotyped with the four SCAR markers to determine the genetic state concerning the high oleic acid gene (Ol). Results from a Chi square analysis of the observed frequencies of each dominant FAD2-1 marker locus in 143 F2 individuals indicated that the deviation from the expected ratio of 3:1 (high to low oleic acid) was not statistically significant (P< 0.95) from the observed segregation ratio. These results were consistent with the previous finding that an incomplete dominant gene governs sunflower high oleic acid. A multiplex assay of 78 Simple sequence repeat (SSR) markers was optimised and evaluated on 143 plants of the F2 population to determine suitable SSR markers that can be used in a marker-assisted background selection. Only 14 markers were suitable for marker-assisted background selection based on their high polymorphic information content, allele frequency and maximum allele numbers. In conclusion, this study demonstrated the potential of using SSR and SCAR marker systems as a breeding tool to characterise and speed up the selection process in marker-assisted backcross breeding. / Thesis (MSc (Botany))--North-West University, Potchefstroom Campus, 2013.

Globale Megatrends erfordern immer flexiblere analytische Messmethoden und Assays. Insbesondere im Umwelt-, Agrar-, Lebensmittel- und Gesundheitssektor sind chemische Assays hier eine geeignete Wahl. Eine Vielzahl solcher Assays steht in akademischen und industriellen Bereichen zur Verfügung. Die Anpassung an neue Verbindungen hingegen ist oft schwierig zu realisieren, da der einzelne Test meist für einen spezifischen Analyten konzipiert ist. Eine modulare, analytische Plattform für die Entwicklung chemischer Assays ist daher sehr wünschenswert. Ein solches System sollte die Möglichkeit einer schnellen und flexiblen Implementierung verschiedener Erkennungstypen für neue Analyten und die Möglichkeit einer Multiparameter-(Multiplex-)Bestimmung in einem robusten und portablen Auslesegerät beinhalten. Einzelpartikel-basierte, chemische Assays haben sich hier als geeignete Lösung erwiesen. In dieser Arbeit stelle ich Polystyrol-Kern-Silikat-Schale-Partikel als modulare, hybride Plattform für die flexible Konfiguration von Einzelpartikel-basierten chemischen Assays vor. Zunächst wurde ein Verfahren entwickelt, das den Zugang zu verschiedenen-Partikelarchitekturen ermöglicht. Diese Partikel wurden für den DNA-Nachweis bis in den fmol-Bereich getestet (Kapitel 2). Ein neues Werkzeug zur Bestimmung der Rauheit der Partikel aus elektronenmikroskopischen Bildern wurde entwickelt und auf das breite Spektrum der im Projekt hergestellten SiO2@PS-Partikel angewendet (Kapitel 3). Damit soll die Grundlage zur Vergleichbarkeit zwischen zukünftigen Partikelcharakterisierungen geschaffen werden. Schließlich wurde ein Multiplex-Assay mit farbstoffkodierten, Protein-abweisenden Partikeln entwickelt, um kleine Moleküle durch immunochemische Reaktionen in einem waschfreien Verfahren nachzuweisen (Kapitel 4). Letzteres verdeutlicht, dass eine hohe analytische Leistung mit neuem Potenzial an flexibler Funktionalität durch die Verwendung hybrider SiO2@PS-Partikel kombiniert werden kann. / Global megatrends such as demographic change, personalization, climate change or urbanization demand for increasingly flexible and mobile analytical measurement methods and assays. Especially in the environmental, agricultural, food and health sectors, chemical assays are a suitable choice. A large variety of such assays is available in the academic and industry area. However, their modification to measure new compounds is time-consuming and laborious, because they are typically designed to detect a specific single analyte. A modular platform for chemical assay development is thus highly desirable. Such a system should include the possibility for fast, easy and flexible implementation of various recognition types towards emerging analytes and the possibility for multi-parameter (multiplexed) detection in a potentially portable fashion. Single particle-based assays have proven to be an adequate solution here. In this work, I present hybrid polystyrene core-silica shell (SiO2@PS) particles as new spherical substrates for the flexible configuration of single particle-based chemical assays. First, a procedure to control the surface topology of the beads was developed, giving access to smooth, raspberry-like or multilayer-like CS structures. These particles were used for DNA detection down to the fmol-level (Chapter 2). A new tool to extract the roughness of the particles from electron microscopy images was developed next and applied to the wide range of CS beads prepared throughout the project (Chapter 3). This general protocol provides the basis for the comparability of future CS particle characterization. Finally, a multiplex assay with dye-encoded beads with non-fouling surfaces was developed to detect small molecules via immunochemical reactions in a wash-free procedure (Chapter 4). The latter ultimately proves that hybrid CS particles can combine high analytical performance and unmatched potential for flexible functionality. / Suspension Array Technology