Stability of Proteins in Dried Blood Spot Biobanks

Abstract

An important motivation for the construction of biobanks is to discover biomarkers that identify diseases at early, potentially curable stages. This will require biobanks from large numbers of individuals, preferably sampled repeatedly, where the samples are collected and stored under conditions that preserve potential biomarkers. Dried blood samples are attractive for biobanking because of the ease and low cost of collection and storage. Here we have investigated their suitability for protein measurements. Ninety-two proteins with relevance for oncology were analyzed using multiplex proximity extension assays (PEA) in dried blood spots collected on paper and stored for up to 30 years at either +4 °C or −24 °C.Our main findings were that (1) the act of drying only slightly influenced detection of blood proteins (average correlation of 0.970), and in a reproducible manner (correlation of 0.999), (2) detection of some proteins was not significantly affected by storage over the full range of three decades (34 and 76% of the analyzed proteins at +4 °C and −24 °C, respectively), whereas levels of others decreased slowly during storage with half-lives in the range of 10 to 50 years, and (3) detectability of proteins was less affected in dried samples stored at −24 °C compared with at +4 °C, as the median protein abundance had decreased to 80 and 93% of starting levels after 10 years of storage at +4 °C or −24 °C, respectively. The results of our study are encouraging as they suggest an inexpensive means to collect large numbers of blood samples, even by the donors themselves, and to transport, and store biobanked samples as spots of whole blood dried on paper. Combined with emerging means to measure hundreds or thousands of protein, such biobanks could prove of great medical value by greatly enhancing discovery as well as routine analysis of blood biomarkers.

Metabolic profiles derived from residual blood spot samples: A longitudinal analysis

“…In Ontario, Canada, samples are stored for 19 years before they are destroyed 13 . Protein, DNA and other potential targets from dried blood spots have been shown to be stable over many years 14 17 . However, the stability of individual analytes used to interpret newborn screening profiles after exposure to different storage conditions has been found to be largely variable.…”

Improved Dried Blood Spot-Based Metabolomics: A Targeted, Broad-Spectrum, Single-Injection Method

“…The benefits of dried blood spots are of particular interest for comparative metabolomics studies conducted in remote locations, and those having large cohorts from multiple collaborating centers [9]. In recent years, due to the above benefits, DBS have also been increasingly used in various other fields, such as therapeutic drug and abused substances monitoring [8,10], pharmacokinetics [11], proteomics [12], lipidomics [13,14], and metabolomics [15][16][17][18].…”

A myopic perspective on the future of protein diagnostics

“…2). We furthermore found that the levels of most proteins remained stable upon storage for tens of years [41]. For those proteins whose levels showed a tendency to slowly decrease over time, storage at −24°C better preserved levels than did +4°C This means that very large biobanks can be built at little cost by simply drying drops of blood on paper and preserving these cold.…”