The quantities of these chemicals can reveal many things about the various organs of the body. Most veterinary chemistry panels check blood electrolyte and for diseases of the liver , kidneys and pancreas.
Whole blood is a combination of blood cells and liquid.
The chemistry panel deals with the liquid portion of the sample after the cells have been removed. To obtain the liquid, the blood sample is allowed to clot within the tube and then the tube is spun in a centrifuge. This forces the clot to the bottom of the tube and the liquid remains at the top. This is the portion used for a chemistry panel. For larger panels, the tests are often performed by a local laboratory, frequently within a human hospital.