Swtor midichlorians count
Without the midi-chlorians, life could not exist, and we would have no knowledge of the Force. They continually speak to us, telling us the will of the Force. When you learn to quiet your mind, you'll hear them speaking to you."
Midi-chlorian counts were measured through a blood test; the Jedi used this method to locate Force-sensitive children Empire, research into Jedi and the Force was banned, and though midi-chlorians continued to be tested for, sometimes by the Empire itself to root out hidden Jedi and other Force-sensitives.