In response to stability issues with our current batch of APTT reagent (Triniclot Batch 125002) on the Stago STAR/Evolution an evaluation of an alternative APTT reagent (Cephascreen Batch 110191) was undertaken.
The new reagent was assessed for convenience, on-board stability, reference range, factor sensitivity (FXII, FXI, FIX, FVIII), UF-Heparin sensitivity and Lupus Anticoagulant sensitivity. Cephascreen does not require installation of a stir bar (with all associated contamination risks) to keep the reagent suspended. Batch to batch variation was not assessed.
The reference ranges for APTT are comparable at 23.9 – 36.4 seconds (Triniclot) and 23.3 – 35.1 seconds for Cephascreen. Heparin sensitivity is similar with therapeutic level of 64 - 86 seconds (Triniclot) and 71 – 95 seconds for Cephascreen. Factor sensitivity for FXII, FXI, FIX and FVIII are similar at approximately 35%, 40%, 35% and 50% respectively for Triniclot and 20%, 40%, 35% and 50% for Cephscreen. Initial investigations show acceptable lupus sensitivity.
Cephascreen appears to be a more convenient and suitable replacement for Triniclot APTT reagent with similar properties and acceptable variances.