> Several studies suggest that small volumes of blood have too much variance to yield useful test results. That's misrepresenting it a bit. Currently there are

> Several studies suggest that small volumes of blood have too much variance to yield useful test results. That's misrepresenting it a bit. Currently there are zero blood tests that have a 100% accuracy therefore if you can't do a normal test with an accuracy near 100% you're not going to be able to do it with a smaller subset of data. However, if we get to the point of 100% accuracy (or at least near) then there is no reason why those types of tests couldn't be useful. But yes today they are not.