Red blood cells
Cells containing hemoglobin transport oxygen and nutrients to all parts of the body and remove carbon dioxide and waste. Red blood cells are used for more than 70 percent of all transfusions and can be stored out of the body for up to 42 days.

White blood cells
White blood cells protect the body against disease and infection. They move through the blood stream to attack and absorb bacteria.

Platelets
Platelets are small cells in the blood that induce clotting and control bleeding. They can be stored out of the body for up to five days.

Plasma
Plasma is a pale yellow mixture of water, proteins, and salts which act as a carrier for blood cells, nutrients, enzymes, and hormones. It can be kept in a frozen state for up to a year.