Serum total protein

Serum total protein,also known as total protein, is a biochemical test for measuring the total amount of protein in serum.

Protein in the plasma is made up of albumin and globulin. The globulin in turn is made up of α1, α2, β, and γ globulins. These fractions can be quantitated using protein electrophoresis, but the total protein test is a faster and cheaper test that estimates the total of all fractions together. The traditional method for measuring total protein uses the biuret reagent, but other chemical methods such as Kjeldahl method, dye-binding and refractometry are now available. The measurement is usually performed on automated analysers along with other laboratory tests.

Interpretation

The reference range for total protein is typically 60-80g/L. (It is also sometimes reported as "6.0-8.0g/dl"), but this may vary depending on the method of analysis.

• Concentrations below the reference range usually reflect low albumin concentration, for instance in liver disease or acute infection. Rarely, low total protein may be a sign of immunodeficiency.
• Concentrations above the reference range are found in paraproteinaemia, Hodgkin's lymphoma, leukaemia or any condition causing an increase in immunoglobulins. Total protein is also commonly elevated in dehydration and C677T gene mutation.

Reference ranges for blood tests, with total plasma protein (shown in purple at right) with other constituents.

External links

• Total protein and A/G ratio at Lab Tests Online
• Total protein: analyte monograph - The Association for Clinical Biochemistry and Laboratory Medicine