Serum biochemical parameters
TOTAL Protein assay
Dr. Samah Kotb
Lecturer of Biochemistry
2015

What do you know about liver function

• 1. Total and conjugated bilirubin
• 2. ALT
• 3. AST
• 4. Total protein
• 5. GGT
• 6. ALP
• 7. 5′-nucleotidase
• 8. Albumin
• 9. prothrombin time

•
Total protein was estimated according to the method of (Burtis A and Koller A ., 1999) ,
Colorimetric method.

• Proteins give an intensive violet –blue complex with copper salts in an alkaline medium. Iodide is included as an antioxidant.

• The intensity of the color formed is proportional to the total protein concentration in the sample.

• Total protein Standard : Bovine serum albumin standard (7g/dL)
(70 g/L).
• Biuret reagent: R1
• Sodium Potassium tartrate (21 mmol/L)
• Sodium hydroxide (0.75 mol/L)
• Potassium iodide (6 mmol/L)
• Cupric Sulfate (6 mmol/L)

• 1- 1 ml of Biuret reagent was added into both unknown test and control tubes, then 0.02 ml of serum were added to unknown.

• 20.02 ml of Bovine albumin primary standard and
1 ml of Biuret reagent were added into standard tube, 1 ml of Biuret reagent was added into blank tube.

• 3- The contents were mixed well, incubated at 37°C for 5min, standard and blank tubes.

• 4- The absorbance read at 540 nm.
• 5- Blank was used for zero adjustment of standard, and the test.

• A sample
• Concentration of protein ( g/dL) =
• Where: A standard x 7.0
• A: absorbance of recorded sample
• 7.0: Standard concentration

• Adults: 6.6-8.7 g/dL (66-87g/L).
• Prematures: 3.6-6.0 g/dL (36-60 g/L).
• Newborns : 5.3-8.9 g/dL (53-89 g/L)
• Pregnancy: Concentration lowers from 69 to
61 g/L