Demonstration of a Frozen Sample Aliquotter to Prepare Plasma and Serum Aliquots Without Thawing Frozen Parent Samples

Abstract

Human biospecimens represent invaluable resources to advance molecular medicine, epidemiology, and biomarker discovery/validation, among other biomedical research. Biobanks typically cryopreserve biospecimens to safeguard their biochemical composition. However, exposing specimens repeatedly to freeze/thaw cycles can degrade their integrity in unforeseen ways. Those biobanks storing liquid samples, thus, regularly make a fundamental compromise at collection time between freezing samples in many small volumes (e.g., 0.5 mL or smaller) or in fewer, larger volumes (e.g., 1.8 mL). The former eliminates the need to expose samples to repeated freeze/thaw cycling, although increasing up-front labor costs, consumables used, and cold storage space requirements. The latter decreases up-front labor costs, consumables, and cold storage requirements, yet exposes samples repeatedly to damaging freeze/thaw cycles when smaller aliquots are needed for analysis. The Rhode Island BioBank at Brown University (RIBB) thoroughly evaluated the performance of an original technology that minimizes a sample's exposure to freeze/thaw cycling by enabling the automated extraction of frozen aliquots from one single frozen parent sample without thawing it. A technology that eliminates unnecessary sample exposures to freeze/thaw cycles could help protect sample integrity, extend its useful life, and effectively rectify and eliminate the aforementioned need to compromise. This report presents the results of the evaluation, and conclusively demonstrates the technology's ability to extract multiple uniform frozen aliquots from a single cryotube of never-thawed frozen human plasma, which faithfully represent the parent sample when analyzed for typical biochemical analytes, showing a coefficient of variability lower than 5.5%.

Proteomics in Diagnosis: Past, Present and Future

“…Many authors have repeatedly stated that a majority of low abundance and/or low molecular weight proteins deteriorate either in quality or quantity or both upon repeated freeze-thaw cycles which for some proteins(such as VEGF) is as low as 1 F/T cycle [50]. The ideal practice to avoid sample stability issues is to make one time use aliquots of the total sample volume and prevent repeated freeze thaw cycles of the entire sample quantum [50]. Even these aliquots should be thawed on ice to prevent any damage to the sample.…”

“…In such cases samples should be immediately snap frozen in liquid nitrogen and sealed in a sterile cryocans [50]. In any case the sample must finally be kept at -80 ˚C or liquid nitrogen for long term storage.…”

Blood-borne biomarkers and bioindicators for linking exposure to health effects in environmental health science

“…For cryopreservation, dimethyl sulfoxide (DMSO) is added to cells as a cryoprotectant, and samples are stored in liquid nitrogen vapor to prevent cell death (Holland et al 2005;Vaught 2006). Ellis and Venturini (2013) also showed that blood samples may be frozen in larger volumes and that frozen aliquots removed from the stock solution without thawing the samples and without a significant loss in sample integrity, thereby decreasing the number of sample tubes needed to store multiple aliquots. While high levels of reproducibility were observed for cholesterol, triglycerides, glucose, and immunoglobulin G, the effectiveness of this technique for other analytes in blood may vary (Ellis and Venturini 2013).…”

“…Ellis and Venturini (2013) also showed that blood samples may be frozen in larger volumes and that frozen aliquots removed from the stock solution without thawing the samples and without a significant loss in sample integrity, thereby decreasing the number of sample tubes needed to store multiple aliquots. While high levels of reproducibility were observed for cholesterol, triglycerides, glucose, and immunoglobulin G, the effectiveness of this technique for other analytes in blood may vary (Ellis and Venturini 2013). Blood samples are commonly stored in biorepositories, such as the European Cancer Study biorepository, which contains more than 380,000 blood samples.…”