The Effect of Tropical Temperatures on the Quality of RNA Extracted from Stabilized Whole-Blood Samples.

Whole-blood-derived transcriptional profiling is widely used in biomarker discovery, immunological research, and therapeutic development. Traditional molecular and high-throughput transcriptomic platforms, including molecular assays with quantitative PCR (qPCR) and RNA-sequencing (RNA-seq), are dependent upon high-quality and intact RNA. However, collecting high-quality RNA from field studies in remote tropical locations can be challenging due to resource restrictions and logistics of post-collection processing. The current study tested the relative performance of the two most widely used whole-blood RNA collection systems, PAXgene and Tempus™, in optimal laboratory conditions as well as suboptimal conditions in tropical field sites, including the effects of extended storage times and high storage temperatures. We found that Tempus™ tubes maintained a slightly higher RNA quantity and integrity relative to PAXgene tubes at suboptimal tropical conditions. Both PAXgene and Tempus™ tubes gave similar RNA purity (A260/A280). Additionally, Tempus tubes preferentially maintained the stability of mRNA transcripts for two reference genes tested, () and (), even when RNA quality decreased with storage length and temperature. Both tube types preserved the rRNA transcript () equally. Our results suggest that Tempus blood RNA collection tubes are preferable to PAXgene for whole-blood collection in suboptimal tropical conditions for RNA-based studies in resource-limited settings.