ALBUMIN Test. lab information about test and diagnosis of diseases.

_______________________________________

ALBUMIN Test. Lab information about test and diagnosis of diseases. 

---

Albumin Test – Manual of Medical Laboratory Techniques

Purpose:
Quantitative estimation of albumin in human serum by photometric method using bromocresol green (BCG) dye binding. Elevated serum albumin levels are associated with dehydration. Low serum albumin levels indicate potential malnutrition, liver diseases, kidney disorders (especially nephrotic syndrome), and rheumatoid arthritis.

Principle:
Albumin acts as a cation at pH 3.8 and selectively binds to the anionic dye bromocresol green, forming a green-colored complex. The intensity of the color, measured at 630 nm, is directly proportional to the concentration of albumin in the sample.

Performance Specifications:

• Linearity: up to 6.0 g/dL
• Measurement range: 0.5–6.0 g/dL
• Sensitivity: 0.5 g/dL
• Specificity: certain drugs (e.g., Ampicillin) may interfere with dye-binding properties. Only human albumin standards should be used.

Primary Sample:

• Use serum (fasting sample recommended).
• Avoid venostasis during collection to prevent hemoconcentration.
• Collect 4 mL venous blood in a plain red vacutainer; allow to clot for 30 minutes.
• Centrifuge at 2500 rpm for 10 minutes.
• Avoid hemolyzed or turbid samples.
• Analyze within 3 hours or store serum at 2–8 °C (up to 30 days).

Reagents and Equipment:

• Reagent: Bromocresol Green (BCG) buffer, pH 3.68
• Standard: Bovine albumin fraction V (5 g/dL)
• Instrument: Semi-auto analyzer (e.g., RA 50)
• Wavelength: 628 nm
• Temperature: 37 °C
• Incubation time: 10 minutes

Procedure:

1. Run reagent blank with distilled water.
2. Process standard, then patient samples.
3. Measure absorbance at 628 nm.

Calculation:

Reference Range:

• Adults: 3.5 – 5.0 g/dL

Critical Values:

• Below 2.0 g/dL indicates severe hypoalbuminemia.

Interpretation:

• Low albumin: liver disease, nephrotic syndrome, malnutrition, chronic illness, or pregnancy.
• High albumin: dehydration.

Potential Sources of Error:

• Hemolyzed serum may give false high values.
• Non-human albumin standards or contaminated reagents may cause inaccurate results.

________________________________________

References:
Ramakrishnan, Manual of Medical Laboratory Techniques, pp. 23–25.

Produce by :Dr. Yousef AL-Adbai

______________THANK_YOU_____________