Where does blood pick up carbon dioxide from?

Most of the carbon dioxide in your body is in the form of bicarbonate. This is made by your kidneys. Bicarbonate is used to keep the acids and bases in your blood in balance. It is carried in the liquid part of the blood called the serum.CO2 can be found as bicarbonate, carbonic acid, and dissolved CO2. The blood picks up CO2 from each and every cell in your body by way of a very tiny capillary.