Fluorescence monitoring of unstained protein bands in acrylamide gel

Equilibrium gel permeation: measurement of solute partitioning by direct fluorescence scanning

The feasibility fo using fluorescence detection in quantitative gel permeation measurements has been explored. It is shown that the effect of scattering by the gel matrix can be evaluated in terms of pathlength-dependent turbidity functions for excitation and emission wavelengths. Experimental studies were carried out to evaluate these funcitons in cross-linked dextran gels (Sephadexes) and in agarose gels (Sepharoses). Empirical turbidity functions derived for these gels have a simple form, leading to accurate simplifying approximations for the scattering correction required in a fluorescence gel permeation measurement. Using this approach...

The quantitative measurement of whey proteins using polyacrylamide-gel electrophoresis

A method is described for the quantitative estimation of a mixture of whey proteins by spectrophotometric scanning of the stained protein bands following polyacrylamide-gel electrophoresis. The incorporation of beta-lactoglobulin A as an internal standard improves the accuracy of the technique. The method has been used to measure residual native whey proteins in milk after heating. Results are presented for whey protein denaturation in skim-milk after heat treatment at 130 and 140 degrees C for various periods of time.

Detektion von carboanhydrase isoenzymen in acrylamidgelen mit einem fluoreszierenden sulfonamid

DNSA (1-Dimethylamino-naphthelene-5-sulfonamide) forms with carbonic anhydrase (carbonate hydrolase, EC 4.2.1.1) a highly fluorescent complex [1]. We used the formation of these complexes for the detection of the isoenzyme bands of carbonic anhydrase in isoelectric focusing and electrophoresis in acrylamide gels. DNSA is added to the solution of the isoenzymes before separation. Using quartz tubes - the maximum of the excitation spectrum is 280 nm [1] - for supporting the gels the fluorescent enzyme bands can be observed during development in UV light and without putting the gels out of the quartz tubes. This technique allows the detection of the carbonic anhydrase isoenzymes with greater precision and simplicity than with any staining method.