DefinitionA comprehensive metabolic panel is a group of chemical tests performed on the blood serum (the part of blood that doesn't contain cells).These tests include total cholesterol, total protein, and various electrolytes. Electrolytes in the body include sodium, potassium, chlorine, and many others.The rest of the tests measure chemicals that reflect liver and kidney function.Alternative NamesMetabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20How the test is performedA blood sample is needed. For information on giving a blood sample from a vein, see venipuncture.How to prepare for the testYou should not eat or drink for 8 hours before the test.How the test will feelWhen the needle is inserted to draw blood, so