Volumetric absorptive microsampling: a dried sample collection technique for quantitative bioanalysis.

Volumetric absorptive microsampling (VAMS) is a novel approach to obtaining a dried blood sample for quantitative bioanalysis that overcomes the area bias and homogeneity issues associated with conventional dried blood spot (DBS) sample when a subpunch is taken. The VAMS sampler absorbs a fixed volume of blood (∼10 μL) in 2-4 s with less than 5% volume variation across the hematocrit range of 20-70% with low tip-to-tip variability. There is no evidence of selective absorption by the tip of the plasma component over whole blood. Recommendations for best practice when collecting samples were developed based upon the results of tests examining a number of potential abuse scenarios.