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 (R) and Tempus (TM), 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 (TM) tubes maintained a slightly higher RNA quantity and integrity relative to PAXgene (R) tubes at suboptimal tropical conditions. Both PAXgene (R) and Tempus (TM) tubes gave similar RNA purity (A260/A280). Additionally, Tempus (TM) 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 (TM) blood RNA collection tubes are preferable to PAXgene (R) for whole-blood collection in suboptimal tropical conditions for RNA-based studies in resource-limited settings.

Automated summary

This study compared the performance of two widely used whole-blood RNA collection systems, PAXgene and Tempus, in laboratory and suboptimal tropical field conditions. Tempus tubes maintained higher RNA quantity and integrity compared to PAXgene under suboptimal conditions and also showed better stability of mRNA transcripts for reference genes.