[Roberton3]

In theory, there is no reason why our current diagnostics require the volume of blood that is drawn, or why a smaller sample wouldn't work.  Handling and analysis of smaller volumes is an engineering problem, so there is no reason why Theranos couldn't work.  The problem, of course, is that it is a tricky engineering problem, especially because blood is prone to doing all sorts of things, like clotting, that you might not want it to do (depending on the test).

I'm certainly not an expert in this area, but according to a friend of mine who is, it's actually a physical impossibility to get reliable results from a sample as small as Theranos claimed.  According to him, going smaller than what's commonly used is an engineering problem, but there are limits to how small you can go (essentially a small-sample problem, though he said that was a big oversimplification), and Theranos claimed to be past those limits.  Again, though, I'm far from an expert here -- just going on what I was told.

[Roberton3]

In theory, there is no reason why our current diagnostics require the volume of blood that is drawn, or why a smaller sample wouldn't work.  Handling and analysis of smaller volumes is an engineering problem, so there is no reason why Theranos couldn't work.  The problem, of course, is that it is a tricky engineering problem, especially because blood is prone to doing all sorts of things, like clotting, that you might not want it to do (depending on the test).

I'm certainly not an expert in this area, but according to a friend of mine who is, it's actually a physical impossibility to get reliable results from a sample as small as Theranos claimed.  According to him, going smaller than what's commonly used is an engineering problem, but there are limits to how small you can go (essentially a small-sample problem, though he said that was a big oversimplification), and Theranos claimed to be past those limits.  Again, though, I'm far from an expert here -- just going on what I was told.