Page 5 - Clinical Biochemistry 08PB804

Many high volume tests are done on large automated machines. Less frequently performed
tests may be conveniently carried out by using commercially prepared reagents packaged in
"kit" form. Some analyses are carried out manually.

Types of laboratory tests:

1. Discretionary or on-off tests: Most common clinical biochemistry tests that are designed
to answer specific questions, e.g., does the patient have increased blood urea/glucose
concentration?.

2. Biochemical profiles: These tests are based on the fact that more useful information on the
patients disease status can be obtained by analysing more constituents rather than one e.g.,
plasma electrolytes and liver function tests.

3. Dynamic function tests: These tests are designed to measure the body's response to external
stimulus e.g., oral glucose tolerance test.

4. Screening tests: These tests are commonly employed to identify the inborn errors of
metabolism, and to check the entry of toxic agents (pesticides, lead, mercury) into the body.

5. Emergency tests is frequently used in the clinical laboratory. It refers to the tests to be
performed immediately to help the clinician for proper treatment of the patient e.g., blood
glucose, urea, serum electrolytes.

Identification of patients and specimens:

The correct patient must be appropriately identified on the specimen and request form, as
follows:

1. Patient identification data (PID). This usually comprises name plus unique number.

2. Test request information. This includes relevant clinical details, the tests to be performed
and where the report is to be sent.

3. Collection of specimens. In the correct tube and the appropriate preservative.

4. Matching of specimens to requests. Each specimen must be easily and unequivocally
matched to the corresponding request for investigations.

Different collection tubes