The purpose of this study is to assess the quality of spaceflight tissues stored in Ames Life Science Data Archive (ALSDA) freezers. Garnering information – for downstream functional analysis such as generation of omics datasets – from tissues is, in part, dependent on the state of sample preservation. To assess the viability of a select group of tissues, RNA integrity number (RIN) values were calculated for RNA extracted from rodent livers. Rat livers from Space Launch System 1 (SLS-1) and mouse livers from Commercial Biomedical Test Module 3 (CBTM-3), Rodent Research 1 (RR1), and Rodent Research 3 (RR3) were tested. It was found that mean RIN values from CBTM-3, RR1, and RR3 were suitable for downstream functional analysis (RIN > 5) while the mean RIN value for SLS-1 was not (RIN = 2.5 ± 0.1). Information from this study could lay the foundation for future efforts in determining the types of assays that are most appropriate for different tissues in ALSDA freezers, which would maximize the scientific return on rare spaceflight samples.
RNA integrity numbers will be determined for rat and mouse liver specimens stored at -70ºC to -80ºC. We hypothesize that the RNA of specimens stored in the ALSDA freezers may vary across all specimens and that RIN analyses will confirm sample viability for downstream functional omics analyses.
The study will be conducted on rat liver specimens from SLS-1 (1991) and SLS-2 (1993) and mouse specimens from RR1 (2014) and RR3 (2016). It will be ensured that aliquots from a single animal will not be depleted.
RIN values will be calculated using GeneLab’s bioanalyzer. These values will be plotted against time to assess if there is a temporal trend. A positive control, which was determined when the STS-135 mouse liver samples were processed, will also be included.
Although the species varies, this is not a concern. The focus of the study is to examine the ability to garner information from spaceflight specimens stored at -70ºC to -80ºC regardless of the model organism.
RIN values differ between biospecimens held in ALSDA freezers. These difference in RIN values could be attributed to the age, storage method, and fixative used on these tissues. Additional work should be done to expand this study to other organ types and animal models. Assessing the RIN value provided a glimpse into the current state of the biospecimens stored by the ALSDA. This knowledge is a foundation for future studies that can aid Principal Investigators in their assay and biospecimen selection.