system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If i had a nosebleed, would i be able to use that blood from the nosebleed for regular blood testings?
gpt
If you could manage to keep it sterile, get it into a tube and store it properly like really fast then most likely yes. The chances of your being able to achieve this are pretty low though, so you’re probably better off collecting the traditional way.

Blood required for testing need to be fresh, in some cases still alive and uncontaminated by chemicals or microorganisms from the environment. Satisfying all of these is pretty hard if you aren’t in a doctors office where that have proper equipment.