Tens of companies planning to you blood drop analysis may never be successful. Dammit! Biology, why you so hard?
No one likes a big needle going into their aim and drawing lots of blood especially when you know that actual tests need a few microliters of blood / serum / plasma. This and the desire to make testing check and available out in the community has led to a huge interest in droplet blood testing. The big daddy of the segment, Theranos has been dropped a few pegs lately due to wide range of problems even before they encountered this one.
Now scientists at Rice University claim that when you compare series of droplets concentration of things line hemoglobin are not the same and also differ from levels you get in blood drawn from veins.
A bit of a clusterf+++ if you ask me.