Clinical chemistry or clinical pathology is the area of study concerned with the analysis of components/analytes within bodily fluids. It involves the use of different methodologies to derive a value for specific analytes and/or enzymatic activity related to organ function. These tests can be performed on any bodily fluids, but mainly are done on serum and plasma.
Serum is the yellow watery part of blood that is left after blood has been allowed to clot and all blood cells have been removed. This is most easily done by centrifugation, which packs the denser blood cells and platelets to the bottom of the centrifuge tube, leaving the liquid serum fraction resting above the packed cells. This is the initial step before analysis. Plasma is in essence the same as serum, but is obtained by centrifuging the blood without clotting. Plasma is obtained by centrifugation before clotting occurs. The type of test required dictates what type of sample is used.
Clinical chemistry can be sub-categorized into:
- Routine chemistry – commonly ordered blood chemistries (e.g. Renal function, Liver function)
- Special chemistry – tests that require elaborate techniques/methods (e.g. Tumour and Cardiac marker)
- Clinical endocrinology – study of hormones & diagnosis of endocrine disorders (e.g. Thyroid function, reproductive hormones)
- Toxicology – study of drug of abuse & other chemicals (e.g. Cannabinoids, Cocanoids and Nicotine)
- Therapeutic Drug Monitoring – measurement of therapeutic medication levels to optimize dosage.
Depending on the type of test, one may be required to fast, that is, one must not eat or drink anything (except water) from midnight until the blood samples are drawn.
The more sophisticated and expensive tests are referred overseas and may need to be drawn on specific days in order to be included in the weeks’ batch of samples to be shipped via Fed Ex. For more information, please call the laboratory.
Testing Requisition Form