Estimation of total protein in serum – liver function tests

Estimation of total protein in serum

Estimation of total protein in serum


Total protein make about 7 % of body weight

Blood proteins includes albumin , globulins , fibrinogen , regulatory proteins and other types

Total protein test measures the total amount of two classes of proteins in blood (albumin and globulin)

Albumin is synthesized by liver using dietary proteins and removed from blood by kidney

All plasma proteins are synthesized in the liver except Ȣ – globulins , there are different types of globulin called alpha , beta and gamma globulins , Ȣ – globulin made by immune system

Amino acids are the building block of proteins , in turn proteins are the building block of cells and body tissues


Total protein test depend on Biuret method for determination of protein concentration

Biuret reagent is made of NaOH , KOH , and CuSO4 together with Na – K tartarate 

It is a blue reagent turns to violet in presence of protein in alkaline medium

Normal range

Total protein : 6.5 – 8 g %


CuSO4 : color reagent

NaOH , KOH , Na – K tartarate : alkaline medium (working solution)

Standard protein


Reagent Test Standard Blank
Serum 1 ml
St- protein 1 ml
Water 1 ml
Working solution 2.5 ml 2.5 ml 2.5 ml
Mix , stand for 5 min , then read at 546 nm

Serum total protein level increased in


Chronic infection or inflammation as virus C , B


Serum total protein level decreased in:

Malnutrition or malabsorption

Liver disease



Total protein = serum albumin + serum globulin

Serum globulin (g %) = total protein (g %) – serum albumin (g %)

Normal range of globulins: 2.8 – 3.2 g %
Serum globulins level increased in:

Liver disease


Kidney disease

Serum globulins level decreased in:

Liver dysfunction (α , β globulins)

Ratio of albumin / globulin > 1

It must be greater than 1

Increased in high protein in diet

Deceased in liver dysfunction