A Method for Enzymic Extraction and the Measurement of Chloroplast RNA 12

AUTOR(ES)

Fish, Leonard

RESUMO

A method is described for measuring RNA associated with chloroplast thylakoid membranes. Washed thylakoids are incubated with ribonucleases A and T1, under low Mg2+ conditions, to release hydrolyzed RNA into solution. After removing the membranes by centrifugation, the mono- and oligonucleotides are adsorbed by Dowex 1-X2 in miniature columns made from Pasteur pipettes, and then eluted with 2 n HCl. RNA is estimated from the absorbance of the eluate at 260 nanometers, with corresponding values obtained by the orcinol reaction for pentose. Polyacrylamide gel electrophoresis patterns of extracted RNA indicate that our current procedures for preparation of thylakoids results in material containing variable and often significant levels of RNA from 80S ribosomes. Thus values for total RNA cannot be used as a valid estimate for the level of 70S ribosomes associated with these membranes, unless an additional procedure is used to estimate the per cent contamination by 80S ribosomes.

Documentos Relacionados

• A Method for Continuous Measurement of Export from a Leaf 12
• An automated microbiological method for the measurement of vitamin B12
• Use of specific endonuclease cleavage in RNA sequencing-an enzymic method for distinguishing between cytidine and uridine residues.
• Rapid Method for Direct Extraction of mRNA from Seeded Soils
• A NEW METHOD FOR THE MEASUREMENT OF SELF-DIFFUSION*