Norman S. Cohn

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The invertase (EC purified from cell walls of dwarf pea stems to homogeneity has a molecular mass of 64 kilodaltons (kD). Poly(A)+RNA was isolated from shoots of dwarf pea plants, and a cDNA library was constructed using lambda gt11 as an expression vector. The expression cDNA library was screened with polyclonal antibodies against pea cell wall(More)
Reports of changes in DNA content of certain types of cells following exposure to conditions of stress has led to the suggestion that two kinds of DNA may be present. One is genetic DNA, and the other is called "metabolic" DNA. In a further attempt to investigate the possibility of this phenomenon, determinations of DNA content were made on Feulgen-stained(More)
The results of combination treatments of the roots of Vicia faba with certain radiomimetic compounds (8-ethoxycaffeine, maleic hydrazide, beta-propiolactone, potassium cyanide) and x-ray as well as combination treatments of certain radiomimetic compounds with one another were observed to determine whether interaction will occur between chromosomal breaks(More)
Fixed tissue from the base of the fourth internode above the cotyledons of Pisum sativum plants were Feulgen-stained for DNA. In squash preparations three cell types: xylem vessel elements, phloem fibres and phloem sieve tube elements were identified. Measurement of Feulgen absorbance values in 0.5 X 0.5 microns measuring points across each nucleus were(More)
The chemical action and practical application of the Naphthol Yellow S, Alkaline Fast Green, Coomassie Brilliant Blue, Dinitrofluorobenzene and some lesser known protein staining methods have been surveyed with respect to their potentialities for quantitative cytochemical analyses. None of the dyes can be said to bind to any specific protein or group of(More)