Comparison of Microcapillary Blood Sampling Devices for Use in Anti‐Doping

Blood collection is an important facet of anti-doping testing, forming the basis of the hematological module of the athlete biological passport (ABP). Presently, whole blood is collected via venepucture under standardized conditions, in accordance with the World Anti-doping Agency's International Standard for Testing and Investigations (ISTI). Advances in capillary whole blood collection technology now afford the ability to collect microvolumetric capillary whole blood from the upper arm (or other suitable vascular location such as the abdomen) that is "needle-free" and virtually painless. Previous work has demonstrated the suitability and feasibility of capillary whole blood compared with venous using the Tasso+ device. Recently, other microcapillary devices have received FDA approval increasing the options available to the anti-doping community. The present study extends previous work, by collecting microliter capillary whole blood samples via two different FDA approved devices (RedDrop and the Tasso+ device) to compare with venous blood collected simultaneously. Ten participants provided three matched blood samples (2× capillary and 1× venous) in accordance with WADA ABP guidelines for blood sample collection, for a total of 30 samples. Capillary samples from both devices showed excellent laboratory agreement with venous blood for all CBC parameters, with the exception of platelets. Excellent laboratory agreement was also observed between the two microcapillary collection devices. Irrespective of the device, microcapillary blood collection provides a valid alternative to venous blood collection for ABP purposes.