Biochemical tests and their significance in disease diagnosis.
Biochemical Test
Biochemical tests are the tests used for the identification of bacteria species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one species to the other. These differences in carbohydrate metabolism, protein metabolism, fat metabolism, production of certain enzymes, ability to utilize a particular compound etc. help them to be identified by the biochemical tests.
Types of Biochemical Tests:
| Test | Purpose |
| Beta-glucuronidase | To identify E. coli |
| Bile Solubility | To differentiate S. pneumoniae from other alpha-haemoytic streptococci |
| Catalase | To different staphylococci from streptococci |
| Citrate utilization | To differentiate enterobacteria |
| Coagulase | To identify S. aureus |
| DNA-ase | To help identify S. aureus |
| Indole | To differentiate Gram negative rods, particularly E. coli |
| Litmus milk decolorization | To help identify Enterococcus and some clostridia |
| Oxidase | To help identify Neisseria, Pasteurella, Vibrio, Pseudomonas |
| Urease | To help identify Proteus, Morganella, Y. enterocolitica, H. pylori |
| Lysine decarboxylase | To assist in the identification os Salmonella and shigella |
Prothrombin Time
Also known as PT and Pro Time, this test measures how long it takes blood to clot. This coagulation test measures the presence and activity of five different blood clotting factors. This test can screen for bleeding abnormalities, and may also be used to monitor medication treatments that prevent the formation of blood clots.
Comprehensive Metabolic Panel
This test combines the Basic Metabolic Panel with six more tests for a more comprehensive evaluation of metabolic functions, with a focus on organ systems.
Lipid Panel
The lipid panel is a group of tests used to evaluate cardiac risk. It includes cholesterol and triglyceride levels.
Liver Panel
The liver panel is a combination of tests used to assess liver function and establish the possible presence of liver tumours.
Thyroid Stimulating Hormone
This test screens and monitors the function of the thyroid.
Haemoglobin A1C
This test is used to diagnose and monitor diabetes.
Urinalysis
Often the first lab test performed, this is a general screening test used to check for early signs of disease. It may also be used to monitor diabetes or kidney disease.
