Biospecimen Integrity Assessment via Protein Oxidation Markers

The patent applies preliminary action by adding antioxidants (such as vitamin C, vitamin E, or other reducing agents) to the biospecimen samples at the time of collection and processing. This preemptive measure prevents oxidation from occurring during subsequent storage at −20° C., allowing the samples to be stored at convenient temperatures without compromising integrity. The antioxidants are incorporated into the sample matrix before storage, creating a protective environment that maintains protein stability throughout the storage period.

The patent changes the chemical parameter of the storage environment by introducing antioxidants that alter the oxidation-reduction potential of the sample matrix. This chemical modification allows samples to maintain stability at higher temperatures (−20° C.) rather than requiring ultra-low temperature storage (−80° C.). The antioxidants create a reducing environment that prevents protein oxidation, effectively changing the stability parameters of the biospecimens to permit more practical storage conditions.

The patent replaces the mechanical/empirical measurement approach (quantifying protein loss) with a molecular mechanism-based approach (detecting oxidation-specific modifications). Instead of simply measuring whether protein levels have decreased, the method uses mass spectrometry to detect specific oxidation markers such as carbonyl groups, sulfonic acid derivatives, or other oxidative modifications on amino acid residues. This substitution of measurement methodology provides direct evidence of oxidation damage at the molecular level, enabling precise assessment of sample integrity based on the actual chemical damage mechanism rather than indirect proxies.