Total Protein Examination Using the Biuret Method
Ni Putu Yunita Puspitra Sari1*, Aripa Amril2,3, and Muttaminnah2,4
Abstract
Protein is the main cellular component that makes up half of the weight of cells and has an important role in the structure and function of organisms.1Proteins are formed from one or more polypeptides which play a role in forming specific similarities (Figure 1).2Protein has a special function, namely building and maintaining body cells and tissues.2Total protein is all types of protein found in serum or plasma consisting of albumin, globulin and fibrinogen.3Protein analysis can be done in two ways, namely qualitatively and quantitatively. Qualitative protein analysis is by Xanthoprotein reaction, Hopkins-Cole reaction, Millon reaction, Nitropusicide reaction, and Sakaguchi reaction, while quantitative protein analysis is done using the Kjedahl method, formol titration method, Lowry method, visible spectrophotometry (Biuret) method, and UV spectrophotometry method.3 Examination of total protein levels in the blood is carried out using the biuret method which is seen from the color reaction between the alkaline copper reagent and the CO-NH peptide chain which produces a purple color. 4 This method is based on the number of fixed CO-NH chains per unit mass of protein. The working principle of this method is the color equation with copper ions, where the protein in the serum reacts with copper ions in an alkaline (basic) environment, thus forming a purple complex compound whose color intensity is proportional to the total protein content in the blood. 4,5 The intensity of the purple color indicates the total protein content in the sample so that it can be assessed photometrically by measuring its absorbance using a spectrophotometer at a light wavelength of 546 nm. The advantages of the biuret method compared to other methods in measuring total protein levels are that the examination is not affected by temperature, produces different colors in different proteins, has good examination repeatability, and high accuracy, while the disadvantages of the biuret method are low sensitivity and many interfering factors, EDTA samples can interfere with the interpretation of the results.
Keywords
total protein; biuret method; spectrophotometer.
Cite This Article
Sari, N. P. Y. P., Amril, A., Muttaminnah. (2024). Total Protein Examination Using the Biuret Method. International Journal of Scientific Advances (IJSCIA), Volume 5| Issue 6: Nov-Dec 2024, Pages 1081-1085, URL: https://www.ijscia.com/wp-content/uploads/2024/11/Volume5-Issue6-Nov-Dec-No.692-1081-1085.pdf
Volume 5 | Issue 6: Nov – Dec 2024
