Bicarbonate is an electrolyte, a negatively charged ion used by the body to maintain the bodys acid-base (pH) balance. It also works with other electrolytes (sodium, potassium, chloride) to maintain electroneutrality at the cellular level. This test measures the total amount of carbon dioxide (CO2) in the blood. This carbon dioxide is mainly in the form of bicarbonate (HCO3). CO2 is primarily a byproduct of various metabolic processes. Measuring bicarbonate as part of an electrolyte or metabolic panel can help diagnose electrolyte imbalances or acidosis or alkalosis. Acidosis and alkalosis describe abnormal conditions resulting from an imbalance in blood pH caused by excess acid or alkali (base).