The photometric microdetermination of serum total globulins with a tryptophan reaction: a modified procedure.

Photometric microdetermination of total serum globulins by means of a tryptophan reaction.

The Tauber perchioric acid method and the Fischl colorimetric procedure were combined into a quantitative method for tryptophan that is applicable directly to proteins without hydrolysis. The colorimetric tryptophan method was compared with both salt fractionation and electrophoretic methods for 26 normal sera and those from 51 patients with various chronic diseases. Analysis of the results for...

Photometric determination of cerebrospinal fluid total globulin and A/G ratio with a tryptophan reaction.

A previously described colorimetric tryptophan procedure for determination of serum total globulin and A/C ratio was modified so as to increase its sensitivity and suitability for determination of the small amount of globulins present in cerebrospinal fluid. Twenty-seven normal CSF specimens analyzed with the tryptophan method yielded a mean total globulin value of 14.0 ± 3.03 mg./100 ml., and ...

Photometric microdetermination of human gamma globulin. I. Development of a quantitative flocculation-ninhydrin procedure.

Direct photometric determination of globulin in serum.

A convenient method for direct photometric determination of total globulin in serum has been developed using a one-tube, one.reagent system. The analysis is based on a variation of the Hopkins-Cole reaction, in which glyoxylic acid condenses with the tryptophan residues present in globulin to produce a purple color. In the presence of copper and under the conditions of the analysis, color inten...

The Photometric Microdetermination of Tryptophan in Biologic Materials.

A modification of the Fischl (6) glyoxylic acid method for tryptophan was developed which permits the reaction to occur quantitatively in aqueous solution by substitution of 70% HCIO4 (w/v) for concentrated H2S04. Spectral analysis of the chromogen formed showed a strong adsorption band at 365 m1 for pure tryptophan which was 17 times more sensitive than that at 560 mit. Factors were studied wh...