Preservation of Parasite RNA in the Field.

The pathogenesis of malaria is largely attributable to the parasite's ability to modulate its cytoadhesion phenotype. This relates to the multigenic families comprising dozens to hundreds of members, whose expression, often mutually exclusive, allows the parasite to vary its adhesive properties and antigenic appearance. This phenomenon is mainly described for the variant surface antigens that the parasite expresses on the infected erythrocyte. In order to decipher these gene expression spectra and identify potential antigenic candidates and/or targets of therapeutic interest, the analysis of the transcriptomes of the parasites directly isolated from patients with well-defined clinical presentation is important. RNA stabilization is an absolute prerequisite for a precise and accurate transcriptome profiling. Immediate stabilization of RNA of biological samples is therefore necessary to prevent degradation by ribonucleases (RNase) or cellular changes. This chapter described methodology for preserving parasite RNA samples from malaria patients in the field for transcriptome studies.