Use of the dry blood spot cards allows you to collect blood directly, very small samples, rather than having to process down to plasma and the standard methods.
You spot the blood directly on the cards, let it dry, send it back to the lab at ambient temperatures, where the analyst punches out a small disk for extraction of the analytes. You basically use the same organic solvents that you’re typically using with your plasma methods.
You extract the analyte, then do the quantitation in most cases by HPLC tandem aspect.
The big advantages of dry blood spot is you’re using very small samples, saving a number of animals that have been studied and giving you better quality data because you’re collecting more points per animal.
It also enables you to do studies with newborn animals or humans that you can’t typically can’t get enough sample for by standard methods.