Dr Tarso B Ledur Kist
Guest Researcher | Chemistry & Physics
Research Profile
Prof. Tarso B Ledur Kist. Guest researcher at the Institute of Chemistry, Av. Bento Gonçalves 9500, Federal University of Rio Grande do Sul, 91501-970, Porto Alegre, RS, and at PEA, University of São Paulo, Av. Prof. Luciano Gualberto, 158, Butantã, 05508-900, São Paulo, SP, Brazil.
Forewords
Welcome to My Research Hub
Thank you for visiting our website! I am Dr. Tarso B Ledur Kist and in our Labs at the Federal University of Rio Grande do Sul and University of São Paulo we embrace collaboration in the interdisciplinary fields of physics and chemistry.
We focus on the development of capillary electrophoresis instruments that exhibit high 'separation efficiencies' and high 'time efficiencies' (defined as the number of theoretical plates divided by the migration time squared). Time efficiency is defined in subsection 3.5.1.2 and table 5.5 of the book entitled Open and Toroidal Electrophoresis, Wiley 2020.
Additionally we investigate topics that are closely related to capillary electrophoresis, such as optics, fluorescence, and derivatization.
This research and technology have applications in a great variety of fields such as clinical analysis, pharmaceutical analysis, food analysis, and basic research in life sciences in general. It has the potential to improve quality of life, life expectancy, and the ability to provide better health care for everyone.
The goal of this website is to share our research findings, provide access to resources, and foster connections with fellow investigators, students, and anyone interested in the connections among disciplines.
Electrophoresis
Electrodriven separations, also called electrokinetic separation techniques, are largely used in DNA separation and sequencing, food analysis, clinical analysis, pharmaceutical analysis, and many other fields. This is a continuously developing field that significantly increases life quality and expectancy.
My recently published book highlights many unexplored possibilities within the field (Available Here).
Toroidal electrophoresis is one such new development.
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Toroidal capillary electrophoresis with electroosmotic flow.
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Toroidal capillary electrophoresis without electroosmotic flow.
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Tying cooling capillaries around analytical capillaries provides many advantages for capillary Electrophoresis.
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Solitary waves in Capillary Electrophoresis
One important aspect of capillary electrophoresis is temperature control. There is a significant heat generated by the Joule effect due to the high ionic currents, which is a consequence of the application of high voltages. This heat must be efficiently and, preferably, symmetrically removed. Tying cooling capillaries around the analytical capillaries is one such efficient option. (https://doi.org/10.1002/jssc.70081).
There are only a few dozen 'solitary waves' in nature. They differ from solitons in that they break apart in the face of collision events. Applying optical fields during electrophoresis can create solitary waves. This is theoretically predicted here (https://doi.org/10.1103/PhysRevLett.75.1210) (Phys. Rev. Lett. 75: 1210-1213, 1995) and experimentally demonstrated in the following video and publications.
Fluorescence
The field of fluorescent dye labels and stains is continuously and quickly evolving. Small and bright luorescent dyes find applications in fields such as detection in capillary electrophoresis, chromatography, DNA Sequencing, real-time PCR, DNA microarrays, fluorescence in-situ hybridization, FRET, antibody labelling, flow citometry, fluorescence microscopy, fluorescence nanoscopy (STED, SIM, SMLM, PALM, STOR, and MINSTED), and quantum computing, to mention a few.
Important aspects of fluorescent dyes are their brightness, photostability, and Stokes shift. Some of these properties are common within some classes. Here is an update of the structures of the most important classes and their respective shortnames.
The main xanthene subclasses derived from the xanthene core scaffold.
The next figure shows the maximum molecular brightness (Bmax ) as a function of the wavelength of absorption maximum (of the longest wavelength band) (λa,max). Brightnes is defined as the product of molar (decadic) absorption coefficient with fluorescence quantum yield.
There are only three dyes in the whole database (777 entries) which exhibit a brightness value of higher than 110 mм -1 cm -1 in aqueous solutions. There are 164 dyes in the whole database that have brightness values of higher than 50 mм -1 cm -1 in aqueous solutions. This is 21% of the total number of dyes (777). The most impressive thing to note here is that all of these 164 dyes have λa,max values of between 480 and 680 nm, with the exception of only the following six dyes (λa,max , Bmax , class): Atto 465 carboxylate (453 nm, 56.2 mм -1 cm -1 , an acridine dye), Alexa Fluor 700 (702 nm, 51.2 mм -1 cm -1 , non-disclosed), NIR3 (750 nm, 77 mм -1 cm -1 , cyanine), NIR1 (761 nm, 61.6 mм -1 cm -1 , cyanine), HCDO (769 nm, 65.6 mм -1 cm -1 , cyanine), and HCDS (791 nm, 85.3 mм -1 cm -1 , cyanine). There is a simple explanation for this: below 480 nm the Φ f of some dyes is high, but the εmax of all of the dyes is small. The opposite happens above 680 nm as the εmax of many dyes is high, but the Φ f of almost all dyes is small. Luckily, between 480 and 680 nm there are a few dozen dyes with both high εmax and high Φ f values.
Scattergram of molecular fluorescence brightness (Bmax) in aqueous media plotted against λa,max.
There is a sudden increase in the brightness within the blue range (~480 nm). This is mainly caused by the xanthene derivatives, represented by the solid light green shapes (fluoresceins), solid pink shapes (rhodamines), solid light blue shapes (pyronines), solid dark blue shapes (rosamines, empty green diamonds (rhodols), empty green circles (fluorones), empty blue circles (pyrodols and pyrodones), and empty blue squares (rosols). Rhodamines, pyronines and cyanines outperform other dyes because they have the highest brightness values, followed by fluoresceins and borondipyrromethenes. These classes contain the brightest entities among all currently available classes because their molar absorption coefficients are high for their range and their fluorescence quantum yields are also high. The low brightness and low number of bright dyes observed above 700 nm is due to the low Φ f values exhibited by these large and flexible structures (cyanines, squaraines, and merocyanines), however there are no fundamental principles that discourage the search for solutions to these poor performances.Software
Will be uploaded later.
PDF of Some Articles
Books on the Subject
- Kist, T.B.L. Fluorescent Dye Labels and Stains: A Database of Photophysical Properties. 1st Ed., John Wiley & Sons, Hoboken, 2023. ISBNs Hardback: 9781119835134; ePDF: 9781119835141; epub: 9781119835158; oBook: 9781119835165 (Available Here) (Table of contents)
- Kist, Tarso B. L. Open and Toroidal Electrophoresis. John Wiley; 1st Ed. (April 6th). Hard cover: 288 pages, ISBN-10: 1119539404, ISBN-13: 978-1119539407 (Available Here) (Table of contents)
References
Human Health and Clinical Analysis
1) Hartmann, S.; Kist, T.B.L. A review of biomarkers of Alzheimer's disease in noninvasive samples. Biomarkers in Medicine 12, 677-690, 2018.
2) Kaefer, V.; Semedo, J.G.; Kahl, V.F.; Von Borowsky, R. G.; Gianesini, J.; Kist, T.L.; Pereira, P.; Picada, J.N. DNA damage in brain cells and behavioral deficits in mice after treatment with high doses of amantadine. JAT. Journal of Applied Toxicology 30, 745-753, 2010.
3) Abreu, F.O.M.S.; Forte, M.M.C.; Kist, T.B.L.; Honaiser, L.P. Effect of the preparation method on the drug loading of alginate-chitosan microspheres. Express Polymer Letters 4, 456-464, 2010.
4) Abreu, F.O.M.S; Bianchini, C.; Kist, T.B.L.; Forte, M.M.C. Preparation and properties of core-shell alginate-carboxymethylchitosan hydrogels. Polymer International 58, 1267-1274, 2009.
5) Abreu, F.O.M.S.; Bianchini, C; Forte, M.M.C.; Kist, T.B.L. Influence of the composition and preparation method on the morphology and swelling behavior of alginate chitosan hydrogels. Carbohydrate Polymers 74, 283-289, 2008.
6) Kist, T.B.L.; França, L.T.C.; Carrilho, E. A review of DNA sequencing techniques. Quarterly Reviews of Biophysics 35, 169-200, 2002.
7) Bastani, M.; Hillebrand, S.; Horn, F.; Kist, T.B.L.; Guimarães, J.; Termignoni, C. Cattle tick Boophilus microplus salivary gland contains a thiol-activated metalloendopeptidase displaying kininase activity. Insect Biochemistry and Molecular Biology 32, 1439-1446, 2002.
Fundamentals in Capillary Electrophoresis
1) Kist, T.B.L. Cyclic band compression in toroidal capillary electrophoresis delivers an unlimited number of theoretical plates with a quadratic growth in time and a constant peak capacity. Journal of Separation Science 41, 2640-2650, 2018.
2) Kist, Tarso B. Ledur. Number of theoretical plates achievable by a toroidal capillary electrophoresis system. Journal of Separation Science 40, 4619-4627, 2017.
3) Kist, T.B.L.; Mandaji, M. Separation of biomolecules using electrophoresis and nanostructures. Electrophoresis 25, 3492-3497, 2004.
4) Schoffen, J. R.; Mandaji, Marcos; Termignoni, C.; Grieneisen, H.H.; Kist, T.B.L. The propagator (retarded Green function) formalism as a new calculation method to predict the time evolution of bands in capillary electrophoresis and microchannels. Electrophoresis 23, 2704-2709, 2002.
5) Desruisseaux, C.; Slater, G.W.; Kist, T.B.L. Trapping Electrophoresis and Ratchets: A Theoretical Study for DNA-Protein Complexes. Biophysical Journal 75, 1228-1236, 1998.
6) Slater, G. W.; Kist, T.B.L.; Ren, H.; Drouin, G. Recent developments in DNA electrophoretic separations. Electrophoresis 19, 1525-1541, 1998.
7) Kist, T.B.L. Theory of solitary waves in electrophoresis. Electrophoresis 17, n.6, 1173-1180, 1996.
8) Kist, T.B.L. Solitary Waves of Molecular Distributions in Liquids Generated by Electrophoresis and Optical Fields. Physical Review Letters 75, 1210-1213, 1995.
Hardware in Capillary Electrophoresis
1) Mandaji, M.; Rübensam, G.; Hoff, R.B.; Hillebrand, S.; Carrilho, E.; Kist, T.L. Sample stacking in CZE using dynamic thermal junctions II: Analytes with high dpKa/dT crossing a single thermal junction in a BGE with low dpH/dT. Electrophoresis 30, 1510-1515, 2009.
2) Mandaji, M.; Rübensam, G.; Hoff, R.B.; Hillebrand, S.; Carrilho, E.; Kist, T.B.L. Sample stacking in CZE using dynamic thermal junctions I. Analytes with low dpKa/dT crossing a single thermally induced pH junction in a BGE with high dpH/dT. Electrophoresis 30, 1501-1509, 2009.
3) Mandaji, M; Buckup, T; Rech, R; Correia, R; Kist, T. Performance of a sound card as data acquisition system and a lock-in emulated by software in capillary electrophoresis. Talanta 71, 1998-2002, 2007.
4) Hillebrand, S.; Schoffen, J.R.; Mandaji, M.; Termignoni, C.; Grieneisen, H.H.; Kist, T.B.L. Performance of an ultraviolet light-emitting diode-induced fluorescence detector in capillary electrophoresis. Electrophoresis 23, 2445-2448, 2002.
5) De Boni, L.; França, L.T.C.; Grieneisen, H. H.; Janowicz, M.; Kist, T.B.L.; Consiglio, A.R.; Schoffen, J.R.; Stefani, V.; Termignoni, C. Experimental observation of light-induced solitary waves of analyte bands in capillary electrophoresis. Electrophoresis 20, 2493-2500, 1999.
6) Kist, T.B.L.; Termignoni, C.; Grieneisen, H.H. Capillary zone electrophoresis separation of kinins using a novel laser fluorescence detector. Brazilian Journal of Medical and Biological Research 27, 11-19, 1994.
Food Analysis
1) Goersch, M.C.S.; Schäfer, L.; Tonial, M.; De Oliveira, V.R.; Ferraz, A.B.F.; Fachini, J.; Da Silva, J.B.; Niekraszewicz, L.A.B.; Rodrigues, C.E.; Pasquali, G.; Dias, J.F.; Kist, T.B.L; Picada, J.N. Nutritional composition of Eragrostis teff and its association with the observed antimutagenic effects. RSC Advances 9, 3764-3776, 2019.
2) Stoffel, F.; Santana, W.O.; Fontana, R.C.; Gregolon, J.G.N.; Kist, T.B.L.; De Siqueira, F.G.; Mendonça, S.; Camassola, M. Chemical features and bioactivity of grain flours colonized by macrofungi as a strategy for nutritional enrichment. Food Chemistry 297, 124988, 2019.
3) Stoffel, F.; Santana, W.O.; Gregolon, J.G.N.; Kist, T.B.L.; Fontana, R.C.; Camassola, M. Production of edible mycoprotein using agroindustrial wastes: Influence on nutritional, chemical and biological properties. Innovative Food Science & Emerging Technologies 58, 102227, 2019.
4) Homem, R.V.; Dos Santos, A.; Da Silva, H.P.; Evangelista, S.M.; Komeroski, M.R.; Doneda, D.; Rockett, F.C.; Schmidt, H.O.; Rios, A.O.; Schäfer, L.; Rodrigues, C.E.; Kist, T.B.L.; De Oliveira, V.R. Effect of Teff (Eragrostis tef) on Chemical and Technological Quality of Gluten-free Breads. Journal of Culinary Science & Technology 17, 1-14, 2019.
5) Rodrigues, C.E.; Tonial, M.; Schäfer, L.; Pasquali, G.; Kist, T.B.L. Performance of 3-[4-(bromomethyl)phenyl]-7-(diethylamino) coumarin as a derivatization reagent for the analysis of medium and long chain fatty acids using HPLC with LIF detection. Journal of Chromatography B 1100-1, 50-57, 2018.
6) Camargo, L.R.; Silva, L.M.; Komeroski, M.R.; Kist, T.B.L.; Rodrigues, C.E.; Rios, A.O.; Silva, M.M.; Doneda, D.; Schmidt, H.O.; Oliveira, V.R. Effect of whey protein addition on the nutritional, technological and sensory quality of banana cake. International Journal of Food Science and Technology 53, 2617-2623, 2018.
7) Rübensam, G.; Barreto, F.; Hoff, R.B.; Kist, T.L.; Pizzolato, T.M. A liquid liquid extraction procedure followed by a low temperature purification step for the analysis of macrocyclic lactones in milk by liquid chromatography tandem mass spectrometry and fluorescence detection. Analytica Chimica Acta 705, 24-29, 2011.
8) Hoff, R.; Kist, T.B.L. Analysis of sulfonamides by capillary electrophoresis. Journal of Separation Science 32, 854-866, 2009.
9) Hoff, R.B.; Barreto, F.; Kist, T.B.L. Use of capillary electrophoresis with laser-induced fluorescence detection to screen and liquid chromatography tandem mass spectrometry to confirm sulfonamide residues: Validation according to European Union 2002/657/EC. Journal of Chromatography 1216, 8254-8261, 2009.
Optics
1) Kist, T.B.L.; Orsag, M.; Brun, T.A.; Davidovich, L. Stochastic Schrödinger equations in cavity QED: physical interpretation and localization. Journal of Optics. B, Quantum and Semiclassical Optics 1, 251-263, 1999.
2) Khoury, A.Z.; Kist, T.B.L. Trapping state stabilization in a micromaser with a mixed atomic beam. Physical Review. A 55, 2304-2309, 1997.
3) Kist, T.B.L.; Davidovich, L. Effect of atom pairs on the vacuum trapping state in micromasers: A Monte Carlo wave-function approach. Physical Review. A 54, 2510-2513, 1996.
4) Kist, T.B.L.; Khoury, A. Z.; Davidovich, L. Micromaser Dynamics with Collective Effects using the Monte Carlo Wave-Function Method. Coherence and Quantum Optics 7, 337-338, 1996.
Others
1) Garcia, I.M.; Leitune, V. C. B.; Kist, T.L.; Takimi, A.; Samuel, S.M.W.; Collares, F.M. Quantum Dots as Nonagglomerated Nanofillers for Adhesive Resins. Journal of Dental Research 95, 1401-1407, 2016.
2) Laranjo, M.T.; Kist, T.B.L.; Benvenutti, E.V.; Gallas, M. R.; Costa, T.M.H. Gold nanoparticles enclosed in silica xerogels by high-pressure processing. Journal of Nanoparticle Research 13, 4987-4995, 2011.
3) França, L.T.C.; Schmidt, J.E.; Michles, A.; Horowitz, F.; Grieneisen, H.H.; Kist, T.B.L.; Bisch, P. M. Using Spin Coating to Deposit DNA over Flat Surfaces for AFM Imaging. Acta Microscópica 10, 79-82, 2001.
Contact
Please reach out first name followed by dot and last name at gmail dot com.