Subattomole analysis of fluorescein isothiocyanate (FITC) derivatives amino acids is accomplished by combining capillary zone electrophoresis for high-efficiency separation with laser-induced fluorescence high-sensitivity detection. Concentration detection limits range from 5 × 10 -12 molar alanine to 9 -11 lysine, injected in the column; -21 mole contained within ∼1-nanoliter injection volume at limit. The limit corresponds fewer than 6000 molecules onto column and represents an improvement...

We have reported a set of electrokinetically pumped sheath flow nanoelectrospray interfaces to couple capillary zone electrophoresis with mass spectrometry. A separation is threaded through cross into glass emitter. side arm provides fluidic contact buffer reservoir that connected power supply. The potential applied the drives electro-osmosis in emitter pump fluid at nanoliter per minute rates. Our first-generation interface placed flat-tipped Sensitivity was inversely related orifice size...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThree DNA sequencing methods using capillary gel electrophoresis and laser-induced fluorescenceHarold. Swerdlow, Jian Zhong. Zhang, Da Yong. Chen, Heather R. Harke, Ronda. Grey, Shaole. Wu, Norman J. Dovichi, Carl. FullerCite this: Anal. Chem. 1991, 63, 24, 2835–2841Publication Date (Print):December 15, 1991Publication History Published online1 May 2002Published inissue 15 December...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLaser induced thermal lens effect for calorimetric trace analysisN. J. Dovichi and M. HarrisCite this: Anal. Chem. 1979, 51, 6, 728–731Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 1979https://pubs.acs.org/doi/10.1021/ac50042a034https://doi.org/10.1021/ac50042a034research-articleACS PublicationsRequest reuse permissionsArticle Views848Altmetric-Citations172LEARN ABOUT THESE METRICSArticle...

Abstract We report a simple nanospray sheath‐flow interface for capillary electrophoresis. This relies on electrokinetic flow to drive both the separation and electrospray; no mechanical pump is used sheath flow. system was interfaced with an LCQ mass spectrometer. The best results were observed 2‐µm diameter emitter tip 1‐mm spacing between tip. Under these conditions, detection limits (3 σ ) of 100 amol obtained insulin receptor fragment 1142‐1153. efficiency exceeded 200,000 plates this...

Femtogram proteomics: An ultrasensitive capillary zone electrophoresis–mass spectrometry system that is based on an improved nanospray interface has been developed. This used for the analysis of picogram to femtogram amounts E. coli digests; example, over 100 proteins were identified from 16 pg digests by tandem mass spectrometry. AMTs=accurate and time tags. As a service our authors readers, this journal provides supporting information supplied authors. Such materials are peer reviewed may...

Single molecules of alkaline phosphatase are captured in a capillary filled with fluorogenic substrate. During incubation, each enzyme molecule creates pool fluorescent product. After the product is swept through high-sensitivity laser-induced fluorescence detector; area peak provides precise measure activity molecule. Three studies performed on molecules. In first study, replicate incubations same at constant temperature; amount increases linearly incubation time. show range activity; most...

ADVERTISEMENT RETURN TO ISSUEPREVArticleThermal lens calorimetryJ. M. Harris and N. J. DovichiCite this: Anal. Chem. 1980, 52, 6, 695A–706APublication Date (Print):May 1, 1980Publication History Published online21 September 2008Published inissue 1 May 1980https://pubs.acs.org/doi/10.1021/ac50056a003https://doi.org/10.1021/ac50056a003research-articleACS PublicationsRequest reuse permissionsArticle Views760Altmetric-Citations105LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLaser-induced fluorescence of flowing samples as an approach to single-molecule detection in liquidsNorman J. Dovichi, John C. Martin, James H. Jett, Mitchell. Trkula, and Richard A. KellerCite this: Anal. Chem. 1984, 56, 3, 348–354Publication Date (Print):March 1, 1984Publication History Published online1 May 2002Published inissue 1 March 1984https://pubs.acs.org/doi/10.1021/ac00267a010https://doi.org/10.1021/ac00267a010research-articleACS...

We demonstrate the use of capillary zone electrophoresis with an electrokinetically pumped sheath-flow electrospray interface for analysis a tryptic digest sample intermediate protein complexity, secreted fraction Mycobacterium marinum. For electrophoretic analysis, 11 fractions were generated from using reverse-phase liquid chromatography; each was analyzed by CZE-ESI-MS/MS, and 334 peptides corresponding to 140 proteins identified in 165 min mass spectrometer time at 95% confidence (FDR <...

While there is a rich literature on transcription dynamics during the development of many organisms, protein data limited. We used iTRAQ isotopic labeling and mass spectrometry to generate largest developmental proteomic dataset for any animal. Expression nearly 4,000 proteins Xenopuslaevis was generated from fertilized egg neurula embryo. clusters into groups. The cluster profiles accurately reflect major events that mark changes in gene expression patterns early Xenopus development....

For many proteins, aggregation is one part of a structural equilibrium that can occur. Balancing productive versus pathogenic leads to toxicity critical and known involve adenosine triphosphate (ATP) dependent action chaperones disaggregases. Recently second activity ATP was identified, hydrotrope which, independent hydrolysis, sufficient solubilize aggregated proteins in vitro. This novel function postulated help regulate proteostasis vivo. We tested this hypothesis on aggregates found...

Capillary electrophoresis is coupled with a single molecule detector based on laser-induced fluorescence. Individual molecules migrating from the capillary are detected and counted 50% efficiency. Injection of 30 000 analyte generates reproducible peak consisting at least five components. However, injection 3000 or fewer leads to noisy irreproducible peak. Monte Carlo simulation demonstrates that this irreproducibility results molecular shot noise stochastic fluctuations in number injected...

The phylogenetic relationships among 36 validly described species or subspecies within the genus Staphylococcus were investigated by cloning and sequencing their 60 kDa heat-shock protein (HSP60) genes using a set of universal degenerate HSP60 PCR primers. cloned partial DNA sequences from nine aureus strains highly conserved (97-100% sequence similarity; mean 98%), indicating that gene multiple isolates same have little microheterogeneity. At level, similarity members S. aureus, schleiferi,...

A modified flow cytometer has been used to detect attogram quantities of aqueous rhodamine 6G by laser-induced fluorescence analysis. detection limit 28 attograms (35,000 molecules) was obtained, nearly two orders magnitude better than earlier measurements. The in concentration units 1.4 × 10 -13 mole per liter. During the 1-second measurement period, total volume sampled 0.42 microliter. On average, only half a molecule present 6-picoliter probed volume.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTime-resolved thermal lens calorimetryN. J. Dovichi and M. HarrisCite this: Anal. Chem. 1981, 53, 1, 106–109Publication Date (Print):January 1981Publication History Published online1 May 2002Published inissue 1 January 1981https://pubs.acs.org/doi/10.1021/ac00224a027https://doi.org/10.1021/ac00224a027research-articleACS PublicationsRequest reuse permissionsArticle Views372Altmetric-Citations67LEARN ABOUT THESE METRICSArticle Views are the...

Attomole quantities of 4-(dimethylamino)azobenzene-4'-sulfonyl chloride derivatized amino acids are separated by using capillary zone electrophoresis in a mixed acetonitrile/aqueous buffer system. Detection is performed with an on-column thermooptical absorbance detection technique based on 130-mW argon ion pump laser. limits for the concentration analyte injected onto column range from 5 x 10(-8) M methionine to 10(-7) aspartic acid. Only 37 amol and 450 acid contained within subnanoliter...