Stumpf test

P. K. Stumpf, J. Biol. Chem., 169, 367 (1947). The Stumpf test is a quantitative application of the Dische cysteine-sulfuric acid test for estimation of deoxyribonucleic acid. 

Stumpf M, Dobbyn A J, Keller H-M, Hase W L and Schinke R 1995 Quantum mechanical study of the unimolecular dissociation of HO2 a rigorous test of RRKM theory J. Chem. Phys. 102 5867-70... 

In view of the fact that the above techniques examine single fibers embedded in a matrix block, application of the experimental measurements to practical fiber composites may be limited to those with small fiber volume fractions where any effects of interactions between neighboring fibers can be completely neglected. To relate the interface properties with the gross performance of real composites, the effects of the fiber volume fraction have to be taken into account. To accommodate this important issue, a modified version of the fiber pull-out test, the so-called microbundle pull-out test, has been developed recently by Schwartz and coworkers (Qui and Schwartz, 1991, 1993 Stumpf and Schwartz, 1993 Sastry et al., 1993). In... 

At present there is no evidence for a specific acyl-ACP transferase which has high specificity in transferring an acyl moiety to a suitable acceptor. This possibility was tested recently by Oo and Stumpf (1979) with extracts of developing coconut endosperm. Since this tissue synthesizes as its main fatty acid components medium-chain fatty acids (C12 and C14), extracts of this tissue could be employed to test this and other hypotheses concerning chain termination. These extracts displayed an active acyl-ACP hydrolase, but the specificity was essentially identical to that described for other tissues (Ohlrogge et al., 1978b). A specific acyl-ACP transferase for medium-chain acyl-CoAs was not observed. 

Perhaps the main disadvantage of the diphenylamine reaction for de-soxypentose is the lack of sensitivity. In addition, interference in the test by some substances has been shown by certain investigators (17,21,23,44). Three recently proposed methods deserve serious consideration. Cohen (23) has developed a color reaction with tryptophane, while Stumpf (98) has standardized the cysteine reaction originally proposed by Dische (40). Both methods are accurate in the range of 50-500 / g. of DNA. Ceriotti (21) has developed a micromethod (2.5-15 /xg. of DNA) using the reaction of indole with DNA, followed by extraction of the yellow pigment with chloroform. 

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