Controlled Dried Blood Spot Preparation

Example 20

FIG. 33A shows an exemplary case for spotting blood onto porous material that will be used for mass spectral analysis. The cartridge can have a vial with a volume at the center and vials for overflows. A plug, such as a soluble membrane containing a set amount of internal standard chemical, is used to block the bottom of the vial for volume control. A drop of blood is placed in the vial (FIG. 33B). The volume of the blood in the vial is controlled by flowing the extra blood into the overflow vials (FIG. 33B). The blood in the vial is subsequently dissolved in the membrane at the bottom, mixing the internal standard chemical into the blood (FIG. 33B). Upon dissolution of the plug, blood flows to the paper substrate, and eventually forms a dried blood spot having a controlled amount of sample and internal standard (FIG. 33B).