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Total Serum Protein Determination Lab Report

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Introduction
Total serum protein determination is a standard clinical test that is often used for the diagnosis of diseases involving the kidneys, liver or bone marrow and other metabolic or nutritional disorders1. Blood plasma contains approximately 7% proteins by weight and the fluid that remains after the clotting factors are removed from the plasma is the serum2. Albumin and globulin are the most common blood proteins, and the total protein is the combined measure of the two3. The most abundant protein is albumin, which acts as a carrier of many different molecules in the blood and helps maintain blood volume2. The globulin proteins include many enzymes and elements of the immune system such as antibodies and immunoglobulins2. Changes in …show more content…

Alternatively, low levels of these proteins may indicate kidney or liver disorders, inadequate protein intake or protein malabsorption5. In a diseased state, inflammatory mediators affect the efficiency of hepatic protein synthesis resulting in decreased levels of albumin5. Therefore, nutritional risk status can be determined by these tests because an adequate protein intake or absorption is necessary to provide the substrate for building these proteins in the liver5. However, there are clinical limitations to relying solely on this measurement as an indication of nutrition status4. In some cases, it is possible for total serum protein to remain within healthy reference ranges even if there is a fall in albumin levels, due to a concurrent rise in globulin levels4. While useful in the diagnosis of chronic malnutrition, albumin has a long half-life of 20 days6. Consequently, it may not be as reliable at recognising patients at risk or as a monitoring tool in nutrition therapy due to a slow response to changes in levels6,7. Pre-albumin is another protein found in the blood whose function is to transport thyroxine and vitamin A3. It has a half-life of 2 days1,8 and is more commonly used as a determinant of malnutrition as its response to dietary intake is more …show more content…

This method is a chromogenic test that uses biuret reagent to detect the presence of peptide bonds in blood serum12. The active ingredients in the reagent are sodium hydroxide, potassium sodium tartrate and copper sulphate pentahydrate13. The development of a violet colour after incubation at room temperature is indicative of the presence of proteins and peptides in the blood serum12. A coloured coordination complex forms when the copper ions (Cu2+) binds to the deprotonated nitrogen atoms that form the peptide bonds of the amino acids12. Reactions can also occur between Cu2+ and the nitrogen in the amide groups and the imidazole rings12. The colour intensifies after a period of incubation as the alkalinity of the solution increases and more deprotonated nitrogen atoms become available12. The concentration of the protein and the colour intensity are proportional, thereby exhibiting a linear relationship in accordance with the Beer-Lambert law14. Absorbance is measured by spectrophotometer, λmax = 540

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