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This thesis addresses the calibration and testing of the Oak Ridge Institute for Science and Education's (ORISE) Holdup Measurement System 4 (HMS4) for use in quantifying U-235 holdup contained within the Process Gas Piping (PGP) of the K-25 Building. In addition to the calibration and testing performed the feasibility of measuring U-238 as a surrogate for U-235 quantification was conducted. A Performance Testing and Validation Plan (PTVP) was developed for confirming the calibration of the system and collecting test data to qualify the HMS4 system for the intended application (ORISE 2009). Tests performed were in accordance with the PTVP and the results were documented in the Performance Testing and Validation Report (PTVR). In turn, the results have been examined to verify that the HMS4 system functions properly and can be used to reliably measure the residual U-235 in pipes. Measurement parameters such as the Lower Level of Detection (LLD), the Minimum Detectable Activity (MDA), and the Total Measurement Uncertainty (TMU) have been determined and reported. To support decommissioning activities, a rapid reliable radiation detection system is needed to assess the amount of residual U-235 within the PGP of the K-25 Building in Oak Ridge, Tennessee. The HMS4 system has been selected to make the required measurements. Verification measurements are considered necessary to assess the reliability and adequacy of the PGP characterization results to ensure criticality incredibility. The purpose of this document is to evaluate the characteristics of the HMS4 system regarding its applicability for use on the east side of K-25. Additionally, to define the level of confidence that should be associated with each HMS4 measurement.

We propose to develop new non-data aided (NDA) digital feedforward symbol timing estimators for linear and nonlinear modulations, with a view to reducing the sampling rate of the estimators. The proposed estimators rely on the fact that sufficient statistics exist for a signal sampled at the Nyquist rate. We propose an ad hoc extension to the timing estimator based on the log nonlinearity which performs better than existing estimators at this rate when the operating signal-to-noise ratio (SNR) and the excess bandwidth are low. We propose another alternative estimator for operating at the Nyquist rate that has reduced self-noise at high SNR for large rolloff factors. This can be viewed as an extension of the timing estimator based on the square law nonlinearity. For continuous phase modulations (CPM), we propose two novel estimators that can operate at the symbol rate for MSK type signals. Among the class of NDA feedforward timing estimators we are not aware of any other estimator that can function at symbol rate for this type of signals. We also propose several new estimators for the MSK modulation scheme which operate with reduced sampling rate and are robust to carrier frequency offset and phase offset.

Les éléments transposables (ETs) sont des séquences d’ADN capables de se déplacer au sein du génome. Ils sont trouvés chez la plupart des organismes vivants (45% du génome humain). Du fait de leur mobilité, ils créent des mutations et causent des pathologies (par exemple : Cancer, Hémophilie A ...), d’autres ont perdu leur capacité à transposer, on les nomme « séquences ancestrales ». Pour comprendre la régulation des éléments transposables, nous avons choisi la drosophile comme modèle animal car elle contient les différents types d’ETs trouvés chez l’Homme. Mon projet de thèse concerne l’élément I de la drosophile apparenté à la famille LINE (Long Interspersed Nucleotidic Element) chez les mammifères (20% du génome humain). Un croisement entre des mâles Inducteurs ‘I’ possédant des éléments I fonctionnels avec des femelles réactives ‘R’ qu’en sont dépourvus entraînera la forte mobilisation des éléments I dans les ovaires de la descendance femelle. Leur activation est à l’origine de la Dysgénésie des Hybrides du système I-R. Nos résultats précédents ont montré qu’on peut inhiber l’activité de I, en introduisant des fragments de I lui-même. Ce mécanisme pourrait être comparé à une «vaccination génétique». Plus tard, il a été montré que cette régulation implique une voie de l’ARN interférence, celle des piRNA (Piwi interacting RNA). D’autre part il a été démontré que HP1a, une protéine hétérochromatique, était impliquée dans la répression des ETs. De manière surprenante, mes résultats révèlent qu’un allèle de HP1a portant une mutation dans le chromodomaine (CD : Site d’interaction entre HP1a et H3K9me3) est capable de réduire l’activité de l’élément I et de restaurer la fertilité des femelles. Ce phénotype est corrélé avec une baisse significative des transcrits fonctionnels des éléments I. Des analyses par approches bio-informatiques indiquent l’interférence de la protéine HP1a mutée par son CD avec la voie des piRNAs. Cette interférence aboutit à la régulation de l’élément I et de la suppression de la dysgénésie des hybrides. / Transposable elements (TEs) are DNA sequences capable of moving within the genome. They are found in most living organisms (45% of the human genome). Because of their mobility, they create mutations and cause pathologies (for example: Cancer, Haemophilia A ...), others have lost their capacity to transpose, we call them "ancestral sequences". To understand the regulation of transposable elements, we have chosen Drosophila as an animal model because it contains the different types of TEs found in humans. My thesis project is to study the Drosophila element I related to the LINE family (Long Interspersed Nucleotidic Element) in mammals (20% of the human genome). A cross between Inductive 'I' males possessing functional I elements and reactive 'R' females without it will result in the strong mobilization of the I elements in the ovaries of the female offspring. Their activation is at the origin of the Hybrid Dysgenesis of the I-R system. Our previous results have shown that one can inhibit the activity of I by introducing fragments of I itself. This mechanism could be compared to a "genetic vaccination". Later, it was shown that this regulation involves a pathway of RNA interference, that of piRNA (Piwi interacting RNA). On the other hand it has been shown that HP1a, a heterochromatic protein was involved in the repression of ETs. Surprisingly, my results reveal that an HP1a allele carrying a mutation in the chromodomain (CD: Site of interaction between HP1a and H3K9me3) is able to reduce the activity of element I and to restore fertility in females. This phenotype is correlated with a significant decrease in the functional transcripts of the elements I. Bioinformatics analyzes indicate the interference of the HP1a protein mutated by its CD with the piRNAs pathway. This interference results in the regulation of the element I and the suppression of the dysgenesis of the hybrids.

No description available.

Syftet med denna uppsats är att genom intervjuer med nyanlända elever undersöka deras erfarenheter och syn på sin skolsituation. I Malmö, tillskillnad från många andra kommuner i Sverige, börjar alla nyanlända elever i åldrarna 13-16 på en separat mottagningskola. Detta är ett mottagningssystem som fått en hel del kritik. Kritiker menar att detta mottagningssystem isolerar nyanlända elever i onödan. I denna uppsatts lyfts elevernas erfarenheter av och syn på sin skolsituation fram och diskuteras i termer av integration, skolan som fält och erkännande. Elevernas tankar om sin skolsituation kan delas upp i fyra delar:1. Elever känner stor press på att lära sig det "svenska" och framförallt svenska språket, vilket också tycks leda till en negativ syn på det som av elever inte anses vara "svenskt".2. Många elever anser att de saknar en tydlig förankring i samhället utanför Mosaik. Detta exemplifieras bland annat av att eleverna trots att de ser svenska språket som viktigt att lära sig, sällan fått möjlighet att praktisera det svenska språket med någon annan än andra elever eller personal på Mosaik.3. Eleverna har olika uppfattning om Mosaiks roll som socialiserande och upplever ofta en förvirring kring Mosaiks regler och värderingar.4. Eleverna på Mosaik känner sig sedda och erkända.Utifrån dessa fyra delar går det att se att en spänning mellan partikularism och universalism ständigt omgärdar dessa nyanlända elever. Denna spänning syns både i frågan om de nyanlända elevernas integrering eller inte integrering bland andra elever men också i frågan om vad skolan som integrationsplattform ska fyllas med för innehåll.

Due to increasing terrorist threats and illegal proliferation of nuclear material and technology, there is a need for increased research in the area of detection of smuggled fissile material, some of which is designated by the International Atomic Energy Agency as special fissile material. This thesis focuses on a hypothetical scenario in which a terrorist organization has managed to smuggle an amount of special fissile material onto a personal recreational watercraft and sail it into a marina. If the boat could be forced to go through a detector system, then the contents could be interrogated and a determination made of whether any special fissile material was aboard. This thesis examines the hypothesis that active interrogation may be used successfully in the detection of special fissile material in such an environment. It shows that it is feasible to use an active neutron system to detect a significant quantity of special fissile material onboard a small boat via the differential dieaway technique. The MCNP Monte Carlo transport code was used to simulate the use of a pulsed neutron generator to induce fission in the fissile material and then estimate the detector response. The detector modeled was based on elastic scattering-induced recoil protons using pure hydrogen gas. There was a significant difference between the system with and without the presence of fissile material, and the estimated detector response for the system with fissile material present was shown to be sufficiently greater than the response due to background radiation only. Additionally, dose was estimated and found to be small enough that the system would not likely pose a significant radiological health risk to passengers on the boat.

Specific amino acids (i.e. arginine, citrulline, aspartic acid, histamine, glutamic acid and taurine) play significant roles in a number of physiological processes such as neurotransmission, inflammation and cell proliferation. Analytical methods that are capable of measuring these compounds in small volumes are important for in vivo sampling strategies and single cell analysis. Electrophoresis-based methods (e.g. capillary (CE) and microchip (ME) electrophoresis) with fluorescence detection have been applied to determine various biological compounds due to the high separation efficiency, simplicity, very low sample and solvent volume consumption and short analysis time. In this study, selected amino acids were off-line derivatized with naphthalene-2,3-dicarboxaldehyde/cyanide (NDA/CN-). NDA itself is not fluorescent, but can react with primary amines in the presence of cyanide to produce N-substituted 1-cyanobenz[f]isoindole (CBI) derivatives, which are fluorescent. Run conditions (e.g. buffer additives, organic solvent and separation voltage) were optimized for both methods (CE and ME) to obtain baseline separation of the six analytes. Excitation was accomplished using a diode laser (λex = 445 nm and λem = 490 m). Based on five-point calibration curves, both methods showed good linearity in the range of 10 to 0.1 µmolL-1 for each amino acid. Precision with %RSDs of less than 6.9 and 13.2% was obtained from CE and ME, respectively. For CE, the number of plates (N) was greater than 150 000/m, resolution values were more than 3.4 and migration time was between 11.2 to 18.2 min. ME offered a better efficiency (N > 300 000/m) and resolution (Rs > 3.9) with a much shorter analysis time (3.8 min) than the CE method. Limits of detection and quantification were significantly lower than the concentrations measured in microdialysis sample (MD) for both methods. According to the results with MD, it was possible to identify and quantify all analytes using CE and ME method. A portable fluorescence detection system for use with microchip electrophoresis was developed. Using the portable system with ME, limits of detection for the analytes of interest were 250 nmolL-1 – 1.3 μmolL-1, which were adequate for most analyte detection in brain microdialysis samples. (P.S.: some expressions without training) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Aminoácidos específicos (arginina, citrulina, ácido aspártico, histamina, ácido glutâmico e a taurina) apresentam funções importantes em vários processos fisiológicos, tais como neurotransmissão, inflamação e proliferação celular. Métodos analíticos que são capazes de quantificar estes compostos utilizando baixo volume de amostra são importantes para estratégias de amostragem in vivo e análises de célula única. Métodos baseados em eletroforese, como eletroforese capilar (EC) e microchip eletroforético (ME), com detecção por fluorescência têm sido utilizados para determinar vários compostos biológicos, devido à elevada eficiência de separação, simplicidade, baixo consumo de amostra, volume do solvente e o curto tempo de análise. Neste estudo, os aminoácidos selecionados foram derivatizados off-line com naftaleno-2,3-dicarboxaldeído/cianeto (NDA / CN-). NDA não é por si só fluorescente, mas pode reagir com aminas primárias na presença de cianeto para produzir 1-cianobenz[f]isoindoline N-substituídos (CBI), que são derivados fluorescentes. As condições de execução, incluindo aditivos no tampão, solvente orgânico e voltagem de separação foram otimizados para ambos os métodos (EC e ME) visando obter adequada resolução de separação para seis analitos. A excitação foi conseguida utilizando um laser de diodo (λex = 445 nm e λem = 490 m). Com base nas curvas analíticas com cinco pontos, os dois métodos demonstraram uma boa linearidade no intervalo de 10 a 0,1 µmolL-1 para cada aminoácido. Precisão com RSD% menor do que 6,9 e 13,2% foram obtidos a partir da técnica de EC e ME, respectivamente. Para EC, o número de pratos teóricos (N) foi maior do que 150 000 / m, com valores de resolução maiores que 3,4; sendo que o tempo de migração variou entre 11,2-18,2 min. ME ofereceu uma melhor eficiência (N> 300 000 / m) e resolução (Rs> 3,9) com um tempo de análise muito mais curto (3,8 minutos) do que o método aplicando EC. Os limites de detecção e quantificação para ambos os métodos foram significativamente menores do que as concentrações medidas nas amostras de microdiálise (MD). De acordo com os resultados com MD, foi possível identificar e quantificar todos os analitos usando o método de EC e ME. Um sistema portátil de detecção de fluorescência para ser utilizado com microchip eletroforético foi desenvolvido. Usando o sistema portátil com o ME, os limites de detecção para os analitos de interesse foram 250 nmolL-1 – 1,3 μmolL-1, que são adequados para a detecção da maioria dos analitos nas amostras de microdiálise cerebral. (OBS.: algumas expressões sem formação)

Face à une demande sans cesse croissante de haut débit et d’adaptabilité des systèmes existants, qui à son tour se traduit par l’encombrement du spectre, le développement de nouvelles solutions dans le domaine des communications sans fil devient nécessaire afin de répondre aux exigences des applications émergentes. Parmi les innovations récentes dans ce domaine, l’ultra large bande (UWB) a suscité un vif intérêt. La radio impulsionnelle UWB (IR-UWB), qui est une solution intéressante pour réaliser des systèmes UWB, est caractérisée par la transmission des impulsions de très courte durée, occupant une largeur de bande allant jusqu’à 7,5 GHz, avec une densité spectrale de puissance extrêmement faible. Cette largeur de bande importante permet de réaliser plusieurs fonctionnalités intéressantes, telles que l’implémentation à faible complexité et à coût réduit, la possibilité de se superposer aux systèmes à bande étroite, la diversité spatiale et la localisation très précise de l’ordre centimétrique, en raison de la résolution temporelle très fine.Dans cette thèse, nous examinons certains éléments clés dans la réalisation d'un système IR-UWB intelligent. Nous avons tout d’abord proposé le concept de radio UWB cognitive à partir des similarités existantes entre l'IR-UWB et la radio cognitive. Dans sa définition la plus simple, un tel système est conscient de son environnement et s'y adapte intelligemment. Ainsi, nous avons tout d’abord focalisé notre recherché sur l’analyse de la disponibilité des ressources spectrales (spectrum sensing) et la conception d’une forme d’onde UWB adaptative, considérées comme deux étapes importantes dans la réalisation d'une radio cognitive UWB. Les algorithmes de spectrum sensing devraient fonctionner avec un minimum de connaissances a priori et détecter rapidement les utilisateurs primaires. Nous avons donc développé de tels algorithmes utilisant des résultats récents sur la théorie des matrices aléatoires, qui sont capables de fournir de bonnes performances, avec un petit nombre d'échantillons. Ensuite, nous avons proposé une méthode de conception de la forme d'onde UWB, vue comme une superposition de fonctions B-splines, dont les coefficients de pondération sont optimisés par des algorithmes génétiques. Il en résulte une forme d'onde UWB qui est spectralement efficace et peut s’adapter pour intégrer les contraintes liées à la radio cognitive. Dans la 2ème partie de cette thèse, nous nous sommes attaqués à deux autres problématiques importantes pour le fonctionnement des systèmes UWB, à savoir la synchronisation et l’estimation du canal UWB, qui est très dense en trajets multiples. Ainsi, nous avons proposé plusieurs algorithmes de synchronisation, de faible complexité et sans séquence d’apprentissage, pour les modulations BPSK et PSM, en exploitant l'orthogonalité des formes d'onde UWB ou la cyclostationnarité inhérente à la signalisation IR-UWB. Enfin, nous avons travaillé sur l'estimation du canal UWB, qui est un élément critique pour les récepteurs Rake cohérents. Ainsi, nous avons proposé une méthode d’estimation du canal basée sur une combinaison de deux approches complémentaires, le maximum de vraisemblance et la décomposition en sous-espaces orthogonaux,d’améliorer globalement les performances. / Faced with an ever increasing demand of high data-rates and improved adaptability among existing systems, which inturn is resulting in spectrum scarcity, the development of new radio solutions becomes mandatory in order to answer the requirements of these emergent applications. Among the recent innovations in the field of wireless communications,ultra wideband (UWB) has generated significant interest. Impulse based UWB (IR-UWB) is one attractive way of realizing UWB systems, which is characterized by the transmission of sub nanoseconds UWB pulses, occupying a band width up to 7.5 GHz with extremely low power density. This large band width results in several captivating features such as low-complexity low-cost transceiver, ability to overlay existing narrowband systems, ample multipath diversity, and precise ranging at centimeter level due to extremely fine temporal resolution.In this PhD dissertation, we investigate some of the key elements in the realization of an intelligent time-hopping based IR-UWB system. Due to striking resemblance of IR-UWB inherent features with cognitive radio (CR) requirements, acognitive UWB based system is first studied. A CR in its simplest form can be described as a radio, which is aware ofits surroundings and adapts intelligently. As sensing the environment for the availability of resources and then consequently adapting radio’s internal parameters to exploit them opportunistically constitute the major blocks of any CR, we first focus on robust spectrum sensing algorithms and the design of adaptive UWB waveforms for realizing a cognitive UWB radio. The spectrum sensing module needs to function with minimum a-priori knowledge available about the operating characteristics and detect the primary users as quickly as possible. Keeping this in mind, we develop several spectrum sensing algorithms invoking recent results on the random matrix theory, which can provide efficient performance with a few number of samples. Next, we design the UWB waveform using a linear combination of Bsp lines with weight coefficients being optimized by genetic algorithms. This results in a UWB waveform that is spectrally efficient and at the same time adaptable to incorporate the cognitive radio requirements. In the 2nd part of this thesis, some research challenges related to signal processing in UWB systems, namely synchronization and dense multipath channel estimation are addressed. Several low-complexity non-data-aided (NDA) synchronization algorithms are proposed for BPSK and PSM modulations, exploiting either the orthogonality of UWB waveforms or theinherent cyclostationarity of IR-UWB signaling. Finally, we look into the channel estimation problem in UWB, whichis very demanding due to particular nature of UWB channels and at the same time very critical for the coherent Rake receivers. A method based on a joint maximum-likelihood (ML) and orthogonal subspace (OS) approaches is proposed which exhibits improved performance than both of these methods individually.

La cartographie peptidique est une méthode qui permet entre autre d’identifier les modifications post-traductionnelles des protéines. Elle comprend trois étapes : 1) la protéolyse enzymatique, 2) la séparation par électrophorèse capillaire (CE) ou chromatographie en phase liquide à haute performance (HPLC) des fragments peptidiques et 3) l’identification de ces derniers. Cette dernière étape peut se faire par des méthodes photométriques ou par spectrométrie de masse (MS). Au cours de la dernière décennie, les enzymes protéolytiques immobilisées ont acquis une grande popularité parce qu’elles peuvent être réutilisées et permettent une digestion rapide des protéines due à un rapport élevé d’enzyme/substrat. Pour étudier les nouvelles techniques d’immobilisation qui ont été développées dans le laboratoire du Professeur Waldron, la cartographie peptidique par CE est souvent utilisée pour déterminer le nombre total de peptides détectés et leurs abondances. La CE nous permet d’avoir des séparations très efficaces et lorsque couplée à la fluorescence induite par laser (LIF), elle donne des limites de détection qui sont 1000 fois plus basses que celles obtenues avec l’absorbance UV-Vis. Dans la méthode typique, les peptides venant de l’étape 1) sont marqués avec un fluorophore avant l’analyse par CE-LIF. Bien que la sensibilité de détection LIF puisse approcher 10-12 M pour un fluorophore, la réaction de marquage nécessite un analyte dont la concentration est d’au moins 10-7 M, ce qui représente son principal désavantage. Donc, il n’est pas facile d’étudier les enzymes des peptides dérivés après la protéolyse en utilisant la technique CE-LIF si la concentration du substrat protéique initial est inférieure à 10-7 M. Ceci est attribué à la dilution supplémentaire lors de la protéolyse. Alors, afin d’utiliser le CE-LIF pour évaluer l’efficacité de la digestion par enzyme immobilisée à faible concentration de substrat,nous proposons d’utiliser des substrats protéiques marqués de fluorophores pouvant être purifiés et dilués. Trois méthodes de marquage fluorescent de protéine sont décrites dans ce mémoire pour étudier les enzymes solubles et immobilisées. Les fluorophores étudiés pour le marquage de protéine standard incluent le naphtalène-2,3-dicarboxaldéhyde (NDA), la fluorescéine-5-isothiocyanate (FITC) et l’ester de 6-carboxyfluorescéine N-succinimidyl (FAMSE). Le FAMSE est un excellent réactif puisqu’il se conjugue rapidement avec les amines primaires des peptides. Aussi, le substrat marqué est stable dans le temps. Les protéines étudiées étaient l’-lactalbumine (LACT), l’anhydrase carbonique (CA) et l’insuline chaîne B (INB). Les protéines sont digérées à l’aide de la trypsine (T), la chymotrypsine (CT) ou la pepsine (PEP) dans leurs formes solubles ou insolubles. La forme soluble est plus active que celle immobilisée. Cela nous a permis de vérifier que les protéines marquées sont encore reconnues par chaque enzyme. Nous avons comparé les digestions des protéines par différentes enzymes telles la chymotrypsine libre (i.e., soluble), la chymotrypsine immobilisée (i.e., insoluble) par réticulation avec le glutaraldéhyde (GACT) et la chymotrypsine immobilisée sur billes d’agarose en gel (GELCT). Cette dernière était disponible sur le marché. Selon la chymotrypsine utilisée, nos études ont démontré que les cartes peptidiques avaient des différences significatives selon le nombre de pics et leurs intensités correspondantes. De plus, ces études nous ont permis de constater que les digestions effectuées avec l’enzyme immobilisée avaient une bonne reproductibilité. Plusieurs paramètres quantitatifs ont été étudiés afin d’évaluer l’efficacité des méthodes développées. La limite de détection par CE-LIF obtenue était de 3,010-10 M (S/N = 2,7) pour la CA-FAM digérée par GACT et de 2,010-10 M (S/N = 4,3) pour la CA-FAM digérée par la chymotrypsine libre. Nos études ont aussi démontrées que la courbe d’étalonnage était linéaire dans la région de travail (1,0×10-9-1,0×10-6 M) avec un coefficient de corrélation (R2) de 0,9991. / Peptide mapping is a routine method for identifying post-translational modifications of proteins. It involves three steps: 1) enzymatic proteolysis, 2) separation of the peptide fragments by capillary electrophoresis (CE) or high performance liquid chromatography (HPLC), 3) identification of the peptide fragments by photometric methods or mass spectrometry (MS). During the past decade, immobilized enzymes for proteolysis have been gaining in popularity because they can be reused and they provide fast protein digestion due to the high ratio of enzyme-to-substrate. In order to study new immobilization techniques developed in the Waldron laboratory, peptide mapping by CE is frequently used, where the total number of peptides detected and their abundance are related to enzymatic activity. CE allows very high resolution separations and, when coupled to laser-induced fluorescence (LIF), provides excellent detection limits that are 1000 times lower than with UV-Vis absorbance. In the typical method, the peptides produced in step 1) above are derivatized with a fluorophore before separation by CE-LIF. Although the detection sensitivity of LIF can approach 10 12 M for a highly efficient fluorophore, a major disadvantage is that the derivatization reaction requires analyte concentrations to be approx. 10 7 M or higher. Therefore, it is not feasible to study enzymes using CE-LIF of the peptides derivatized after proteolysis if the initial protein substrate concentration is <10-7 M because additional dilution occurs during proteolysis. Instead, to take advantage of CE-LIF to evaluate the efficiency of immobilized enzyme digestion of low concentrations of substrate, we propose using fluorescently derivatized protein substrates that can be purified then diluted. Three methods for conjugating fluorophore to protein were investigated in this work as a means to study both soluble and immobilized enzymes. The fluorophores studied for derivatization of protein standards included naphthalene-2,3-dicarboxaldehyde (NDA), fluoresceine-5-isothiocyanate (FITC) and 6-carboxyfluorescein N-succinimide ester (FAMSE). The FAMSE was found to be an excellent reagent that conjugates quickly with primary amines and the derivatized substrate was stable over time. The studied substrates were -lactalbumin (LACT), carbonic anhydrase (CA) and insulin chain-B (INB). The CE-LIF peptide maps were generated from digestion of the fluorescently derivatized substrates by trypsin (T), chymotrypsin (CT) or pepsin (PEP), either in soluble or insoluble forms. The soluble form of an enzyme is more active than the immobilized form and this allowed us to verify that the conjugated proteins were still recognized as substrates by each enzyme. The digestion of the derivatized substrates with different types of chymotrypsin (CT) was compared: free (i.e., soluble) chymotrypsin, chymotrypsin cross-linked with glutaraldehyde (GACT) and chymotrypsin immobilized on agarose gel particles (GELCT), which was available commercially. The study showed that, according to the chymotrypsin used, the peptide map would vary in the number of peaks and their intensities. It also showed that the digestion by immobilized enzymes was quite reproducible. Several quantitative parameters were studied to evaluate the efficacy of the methods. The detection limit of the overall method (CE-LIF peptide mapping of FAM-derivatized protein digested by chymotrypsin) was 3.010-10 M (S/N = 2.7) carbonic anhydrase using insoluble GACT and 2.010-10 M (S/N = 4.3) CA using free chymotrypsin. Our studies also showed that the standard curve was linear in the working region (1.0×10-9-1.0×10-6 M) with a correlation coefficient (R2) of 0.9991.