Blair’s medical and science background is the only explanation for how The Thing infects and assimilates, during the scene in which he scans the cells, (which at this point Blair is still human) we find out only a single cell is needed to infect someone.
HOWEVER previously in the film when inspecting The Thing’s corpse Blair touches the corpse (which still has active cells) with his pencil and then proceeds to touch his mouth with the pencil. And yet Blair is still human after this point until sometime later. It’s excusable that Blair didn’t know the assimilation process only takes a single cell so he didn’t take any precautions with touching the pencil to his mouth.
Unfortunatley this rule set doesn’t work for what we see in the movie.
Clark was deemed human via the blood test but he’s the first person to encounter The Thing, the dog literally licks him, transfering saliva. Bennings is also licked by the dog when it first arrives to the camp.
Palmer and Child’s shares a blunt, transferring saliva. Palmer at this scene in the film is assumed to already be assimilated. Childs is human at this point in the film via the blood test which is done after this scene. Even being within close proximitiy to Palmer from sleeping next to him isn’t enough to infect him.
Fuches takes the precaution of getting everyone to eat out of canned food, believing only a single cell is needed to infect. A belief so serious when MacReady talks to him at night he grabs a vial of gasoline ready to self immolate.
The simple fact is: The movie doesn’t work with the single cell theory.
The thing must require some type of prolonged and extreme exposure when assimilating quietly OR loud and extreme exposure when assimilating directly such as when The Thing kills Garry.
Discounting obvious movie logic, otherwise everyone would quarantine and wear respirators with filters, The Thing cannot assimilate with a single cell. Blair’s computer simulation was wrong.
What do you think?
TLDR: A single cell from The Thing cannot infect someone.
ADDITIONAL THINGS:
anyone else notice the dog-thing is bleeding when it first arrived to outpost 31? Lars actually did shoot the dog.