Optimization of a protocol for extraction of Plasmodium falciparum RNA from infected whole blood samples for use in DNA microarrays

This study was carried out to determine the efficiency of two reagents, RNAlater and RNAwiz, for their ability to stabilize Plasmodium falciparum RNA in infected whole blood and saponin lysed parasite pellets for use in DNA microarrays. Eight infected blood samples were stored in each of the reagents, and RNA extracted at days 0 and 56 post collection. RNA yields and quality were compared at the different time points between the two test reagents. We show that for both reagents, higher RNA yields and quality is obtained when RNA is isolated immediately after sample collection (day 0), however, results show that RNAwiz storage provides a marginally higher RNA yield compared to RNAlater storage. Our results indicate that whole blood gave slightly higher RNA yields with superior quality as compared to saponin lysed samples when such whole blood samples are stored in RNA wiz, but not in RNAlater. From our results, we recommend RNAwiz as a better reagent for use in storage of whole infected blood intended for extraction of P. falciparum RNA for DNA microarrays and other sensitive techniques.