Evaluation of two methods for the separation of Plasmodium falciparum messenger RNA

Abstract

The study of gene expression regulation often requires the isolation of mRNA from the total RNA present in the cell. To guarantee the presence of sequences which are not expressed in abundance, it is necessary to obtain mRNA preparations which fully represent the messenger population of the organisms under study. In this work, Plasmodium falciparum mRNA purification efficiency, obtained by two methods, is evaluated: affinity chromatography using oligo dT cellulose columns and mRNA capture by solution hybridisation with an oligo dT primer. Similar mRNA amounts were obtained by the two methods and purification efficiency was between 0.7 and 1.1 % of the total RNA used initially. The size of the cDNA synthesised by the affinity chromatography method (0.4-4 Kb) and by the capture method (0.4-8 Kb), shows that the second method produced longer mRNAs than the first one. The finding of one copy gene clones such as tubulin, actin II, myosin, calmodulin, glucose phosphate isomerase and glucose phosphate dehydrogenase, in cDNA gene libraries, allows us to infer a good expressed sequence representativity in mRNA preparation.