Comparison of three blood collection tubes for 16 biochemical analytes and stability assessment of selected analytes: VACUETTE ^® CAT serum Sep clot activator tube, VACUETTE ^® LH lithium heparin Sep tube, and VACUETTE <sup>®</sup

BackgroundAnalytical performance of VACUETTE® CAT Serum Fast Separator Tube (SFT; Greiner Bio-One, Austria), recently developed quick-clotting serum separator, was evaluated for correlation and stability, comparing with VACUETTE® CAT Serum Sep Clot Activator Tube (SST; Greiner Bio-One) and VACUETTE® LH Lithium Heparin Sep Tube (LiHep Tube; Greiner Bio-One).MethodFor 107 paired samples, 16 analytes (glucose, potassium, LDH, CRP, creatinine, AST, ALT, ALP, GGT, AFP, PSA, TSH, free T4, iPTH, CK-MB, and cardiac troponin I[cTnI]) were measured. Correlations were assessed using Passing-Bablok regression and paired t-tests. Differences were evaluated by comparing the mean percentage difference and estimated difference at medical decision limits (MDLs), to the acceptable desirable difference. For six analytes - glucose, potassium, LDH, AST, iPTH, and cTnI - known for different stabilities between sample types, stability was evaluated by comparing changes over time with desirable differences.ResultsAcross the evaluated range, SFT showed clinically comparable differences to SST, except for CK-MB which showed significant positive bias. Plasma exhibited unacceptable biases: negative for potassium and positive for LDH and CK-MB. Estimated differences at MDLs were acceptable in SFT except for potassium and CK-MB, while plasma showed unacceptable differences in potassium, LDH, creatinine, and CK-MB. LiHep Tube showed reduced stability than SST for all analytes except for iPTH, impairing retest reliability. SFT showed comparable stability except for LDH and iPTH, which showed slightly shortened stability.ConclusionsThe SFT demonstrated high correlation and comparable stability to SST, making it a suitable replacement for the LiHep Tube, as an alternative to SST for rapid testing.