I know this may not be like the real thing, I am not too knowledgeable on blood. If you see something wrong, please tell me!
The rings are red blood call, the white blobs white blood cells. Germs/bacteria/viruses/diseases will eventually appear and destroy red blood cells. They will eventually be destroyed by the white blood cells or simply die.
I tried playing with cloning and it saved automatically, so it's a little messed up now, especially with the counts.