I have a character who trips and twists his knee rather badly while in the outskirts of civilisation, causing a partial tear in a ligament and a respectable amount of swelling. After several hours of misery he's lucky enough to get access to a medical professional with the supplies available to create a sterile field, aspirate around 40 cc of excess fluid from the joint, and do the whole RICE routine. The only thing missing is a lab, so it won't be possible to get the fluid to analysis until it's two days old.
If I read emedicine right, the blood from the ligament shouldn't coagulate, but since the only refrigeration possible is a 12V fridge with a tiny freezing compartment, I suspect that it won't be much point in saving it (for any useful purpose, I mean, since I have a hunch that it'll have to be disposed of by proper incineration rather than chucking it with general rubbish.) Can anyone confirm/disprove?
(Gore stories accepted with relish.)