The blood serum test is a theoretical variant of the blood test which, although hypothesised in the 1982 film The Thing and its 2011 prequel , has never actually been utilized due to sabotage in both films. The simple test involves mixing a suspected imitation's blood with uncontaminated blood; which will hypothetically react if the creature is an imposter. Those performing the test can then observe Thing cells attempting to assimilate the fresh blood.