A blood-test is a method of determining whether a suspected individual has been imitated by The Thing. There are several varieties of test which appear throughout the Thing franchise; most typically performed on a blood sample that is usually extracted from a finger incision or a vein in the arm using a needle.
Blood serum test
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.
- "You see, when a man bleeds, it's just tissue. The blood from one of you Things won't obey when it's attacked. It'll try and survive. Crawl away from a hot needle the same."
- ― MacReady explains his blood test.
Self-preservation blood tests work by coercing autonomous Thing cells (imitating blood cells) to act in self-preservation - for example, crawling away from a hot needle. The method is first seen in the 1982 film The Thing and appears extensively throughout the Dark Horse Comics series. In a bid to determine the identity of the remaining crew of U.S. Outpost 31, helicopter pilot R.J. MacReady develops a rudimentary blood test involving a length of heated copper wire and blood samples taken from the men. Noticing how every part of the Norris-Thing had an instinctive desire to survive, MacReady correctly surmised that a creature's blood would attempt to flee from a hot needle. This blood test was successful in identifying the Palmer-Thing. The 2002 video-game, The Thing, adds a further method of 'self-preservation' testing in the blood test hypo - a portable blood testing device which extracts and exposes a suspect's blood to a caustic chemical agent.