Midi-chlorian

Midi-chlorians were microscopic, intelligent life forms that originated from the foundation of life in the center of the galaxy and ultimately resided within the cells of all living organisms, thereby forming a symbiotic relationship with their hosts. The Force spoke through the midi-chlorians, allowing certain beings to use the Force if they were sensitive enough to its powers. In order to gauge an individual's potential in the Force, blood tests were used to estimate the number of midi-chlorians within the subject's cells, known as an M-count. Anakin Skywalker, the Chosen One, possessed the highest known count in galactic history—over twenty-thousand midi-chlorians—surpassing the potential of Grand Master Yoda and all Jedi.

According to the Sith Lord Darth Sidious, his Sith Master Darth Plagueis could influence the midi-chlorians to create life. In the New Republic Era, Imperial scientist Doctor Penn Pershing experimented with blood samples that he harvested from Grogu, a Force-sensitive youngling with a high midi-chlorian count.

Text and facts from the “Midi-chlorian” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.