Plotline of: Is Red Liz's father or not? is stretching out too long- getting boring

This technologically-savvy FBI unit hasn't done a simple blood test to figure out whether or not Red is Liz's father?!?  Come on!  That part of the storyline is stretching out way too long and is getting boring.  Tell us who Red is already, and move onto other plotlines!!  I don't think I am going to continue watching.....