Blood fights against infection and helps heal wounds. The three main types of cells making up our Blood are the White Blood cells, Red Blood cells and Platelets. White Blood cells have a rather short life cycle, living from a few days to a few weeks. One drop of Blood can contain from 7,000 to 25,000 white Blood cells. If an invading infection fights back and persists, that number will significantly increase.
Platelets form a 'mesh' net to form clots in the Blood to help stop bleeding.
There are about one billion red Blood cells in two to three drops of whole Blood. Red Blood cells live about 120 days in our bodies. Red Blood cells can be stored for up to 42 days. Frozen red Blood cells can be stored for 10 years. Platelets can be stored for only five days.