A new method for the preparation of uniformly 14C-labelled compounds by using Anacystis nidulans

Abstract

1. Growth conditions were devised which enabled Anacystis nidulans to be grown on high specific radioactivity 14CO2 (at over 98% isotopic abundance of 14C) in a closed system with greater than 85% substrate utilization. 2. The DNA and RNA content of A. nidulans was estimated by various methods and compared with that of Chlorella pyrenoidosa. 3. A procedure was developed for the quantitative extraction and separation of the DNA and RNA from A. nidulans. 4. The fractionation and analysis of the DNA and RNA includes methods for the preparation of the uniformly 14C-labelled deoxyribonucleoside monophosphates and the uniformly 14C-labelled ribonucleoside monophosphates. 5. The base 6-methylaminopurine was identified as a component of the DNA. 6. The preparation and total yield of uniformly 14C-labelled amino acids from A. nidulans are also briefly described. The results are discussed in relation to the use of other micro-organisms for the preparation of compounds labelled with 14C.