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, Succinate dehydrogenase complex, subunit A ( SDHA ) and TATA-box-binding protein ( TBP ), even when RNA quality decreased with storage length and temperature. Both tube types preserved the rRNA transcript 18S ribosomal RNA ( 18S ) 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.