Optimized Protocol for Preservation of Human Platelet Samples for Fluorometric Polyphosphate Quantification

Platelet polyphosphate (polyP) can be conveniently quantified by exploiting a recent methodological breakthrough using 4′,6-diamidino-2-phenylindole (DAPI). However, the preservation of these biological samples has not yet been standardized. In preliminary study, potential protocols were screened, while accepted further tested in this study. Pure-platelet-rich plasma (P-PRP) and washed platelet suspensions prepared blood obtained from non-smoking healthy male donors fixed with ThromboFix for 20–24 h at 4 °C. Mass polyP levels determined fluorometer wavelengths 425 525 nm. normalized to counts. Statistical analyses performed non-parametric tests. significantly decreased 20% after 7 days suspension maintained under conditions °C (control). contrast, both P-PRP without significant reduction up 6 weeks removing fixation subsequent freezing pure water −80 Fluorometric quantification often interferes low specificity DAPI binding wavelength used. Our validated will enable long-term high-throughput applied relatively large cohort studies.