Estimation of serum albumin by Dr.Tehmas

ESTIMATION OF
SERUM ALBUMIN
By:
Dr. Tehmas Ahmad Khan,
Demonstrator Biochemistry Department,
Bannu Medical College, Bannu.

Background
 Major Plasma Protein
 Half life of 15—20 days
 Formation:
 Synthesized in the liver as preproalbumin (N-terminal peptide)
 Peptide is removed and nascent protein is released from the rough endoplasmic
reticulum
 The product, proalbumin, is in turn cleaved in the Golgi vesicles to produce the secreted
albumin.
 Released to blood

Normal Range
 Adults
18 – 60 y  3.5 – 5.5 g/dl
 >60 y 3.4 – 4.8 g/dl
 Children
 14-18 y  3.2-4.5 g/dl
 4d-14 y  3.8-5.4 g/dl
 Newborns
0-4 day  2.8-4.4 g/dl

Functions of Albumin
 Maintains Oncotic Pressure
 Transports hormones, in particular, ones that are fat-soluble
 Transports Fatty Acids ("free" fatty acids) to the liver and to myocytes for utilization
of energy
 Transports unconjugated Bilirubin
 Transports many Drugs, serum albumin levels can affect the half-life of drugs
 Competitively binds ions (Ca2+)
 Serum albumin, as acute phase reactant, is a marker of an inflammatory state, is
down regulated.
 Prevents photo degradation of Folic Acid

Hyper Albuminemia
Causes
 Dehydration
 Vitamin A deficiency
Treatment
 Rehydration
 Zn++ supplementation
Note: Hyper Albuminemia is of little to no diagnostic Value in clinical
Practice

Hypo Albuminemia
 Liver disease i.e Cirrhosis of the liver.
 Excess excretion by the Kidneys (Nephrotic Syndrome)
 Excess loss in bowel (protein-losing enteropathy, e.g., Ménétrier's disease)
 Burns (plasma loss in the absence of skin barrier)
 Redistribution (hemodilution increased vascular permeability or decreased lymphatic
clearance)
 Acute disease states (referred to as a negative acute-phase protein)
 Malnutrition and wasting
 Mutation causing analbuminemia (very rare)

Effects of Hypo Albuminemia on Body
 Edema
 Hypotension
 Abdominal Distension (Ascites)
 Lack of appetite
 Muscle Cramps
 Fatigue

Principle
 Measurement of albumin is based on its binding to the indicator dye
bromocresol green (BCG) in pH 4.1
 Forms a blue-green colored complex.
 The intensity of the blue-green color is directly proportional to the concentration of
albumin in the sample.
 It is determined by monitoring light absorbance at 578 nm.
 Reaction:
 Albumin + BCG -----------Albumin-BCG Complex

Requirements
 Bromocresol green
 Acetate Buffer
 Above are mixed and left to stand for 10 mins  yields Working Reagent
 Standard Solution: Concentration of 4g/dl

Precautions
 The only acceptable anticoagulants are heparin and EDTA.
 Fresh Serum to be obtained for Experiment.
 Ideally, after Centrifugation, serum should be immediately separated from blood
cells.
 Do not try to ingest or inhale the Bromocresol Solution. In case of contact, wash
thoroughly and seek medical help.

Procedure
 Take Three Test Tubes and Mark then Unknown(U), Standard(S) and Blank(B).
 Take 1ml of Working Reagent in each tube.
 Add 10 µl of distilled water into Blank(B).
 Add 10 µl of Standard Solution into Test tube marked as Standard(S).
 Add 10 µl of Serum into the test tube marked as Unknown(U).
 Mix and Incubate for 5 minutes at 20—25 degree Celsius.
 Check light absorbance via a calorimeter at 578nm.
 Unknown Absorbance
 Calculation: Albumin concentration (g/dl) = ------------------------------x 4
 Standard Absorbance

Limitations
 Minimum detectable limit of this process in 1g/dl.
 Maximum detectable limit of this process is 7g/dl.
 In case of Hemolysis, increased by more than 13% of Albumin value estimation.
 In Case of Jaundice, Bilirubin Value of more then 40mg/dl leads to decrease in
album value estimation.
 Analytical Value: 1.0—7.0 g/dl

Resources Used:
 Resources used:
 Textbook of Medical Biochemistry by M.N.CHATTERJEA
 Textbook of biochemistry for medical students by Sreekumari and DM Vasudevan
 Wikipedia and Internet

“LIFE IS AN EQUILIBRIUM STATE
BETWEEN DEGRADATION AND
SYNTHESIS OF PROTEINS.”
Yoshinuri Ohsumi,
Nobal Prize Speech in Physiology and Medicine, 2016.

Estimation of serum albumin by Dr.Tehmas

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