New trends in bioanalysis sampling and pretreatment: How modern microsampling is revolutionising the field
overview of current sampling methods
Dried blood spots
- oldest technique (pioneered in the 60s)
- you drip blood on a cellulose card, let it dry, and mail it in
- used for newborn screening (every baby in the newborn world has this done)
- problem: ratio of red blood cells affects how the blood drop spreads on the card and thus how well you can measure it (“hematocrit effect”)
Volumetric Absorptive Microsampling (VAMS)
- market leader (by Neoteryx)
- polymer tip that looks like a pipette tip
- absorbs exactly 10/20/30 µL
Tasso device
- uses micro needles on upper arm instead of finger-tips
- less painful & collects larger volume (up to 500 µL)
Telimmune / Noviplex
- cards with a filtration membrane that separate plasma from whole blood
- red blood cells stay on top, so you get dried plasma instead of dried whole blood