Isotope derivative method

Isotope Derivative Method in Biochemical Analysis, The (Whitehead and Dean). 16 1... 

W14. Whitehead, J. K., and Dean, H. G., The isotope derivative method in biochemical analysis. Methods Biochem. Anal. 16, 1-98 (1968). 

Woolever C, Goldfien A. A double isotope derivative method for plasma progesterone assay. Int J Appl Radiat Isot 1963 14 163-71. 

The isotopic derivative method may help where other methods fail because too little material is available for analysis or the concentration of the component to be determined is too low in the sample. The procedure is useful even where the isotope dilution technique cannot be employed because the substance to be determined is not available in radioactive form. 

The isotopic derivative method is suitable for analysis even of complex naturally occurring mixtures. Thus, classes of hydroxy compounds in vegetable oils have been fractionated through TLC after acetylation with tagged acetic anhydride, identified and quantitatively determined by counting in suspension [419]. 

When Severo Ochoa left the Biochemistry Department at New York University I had to search for another mentor and I was fortunate to be able to continue my graduate work with Albert Keston. While developing the isotope derivative method for amino acid assay we showed for the first time that hydroxyproline was uniquely present in collagen. This observation made a great impression on me. Furthermore, I had the good fortune while at New York University Medical School to meet and to get to know the late Joseph Bunim. It was from him that I learned about the role of collagen in connective tissue and also about collagen diseases. 

Isotope derivative methods, which consist in quantitatively reacting the compound to be determined with a labelled reagent of known specific activity and measuring the activity of the purified product This principle may be applied to enzymatic reactions for the detection of compounds occurring biologically... 

Velick, S. F., Udenfriend, S. J. biol. Chem. 191, 233— 238 (1951). Isotope derivative method, ion-exchange chromatography on Dowex-50 column, PC, and microbiological assay. 

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