Competitive enzyme immunoassay for human plasma fibronectin

Area of Science:

• Biochemistry
• Immunology
• Clinical Chemistry

Background:

• Fibronectin is a crucial extracellular matrix protein involved in cell adhesion, migration, and wound healing.
• Accurate quantification of plasma fibronectin is important for diagnosing and monitoring various medical conditions.
• Existing methods for fibronectin determination may have limitations in sensitivity or specificity.

Purpose of the Study:

• To develop and validate a competitive enzyme immunoassay for the quantitative determination of fibronectin in human plasma.
• To establish the assay's analytical performance characteristics, including its range and sensitivity.
• To assess the assay's utility in detecting fibronectin and related antigens in different biological samples.

Main Methods:

• A competitive enzyme immunoassay was developed using alkaline phosphatase-conjugated rabbit anti-human fibronectin antibodies.
• Polystyrene tubes were coated with purified fibronectin, and incubated with plasma samples and enzyme-labeled antibodies.
• Enzyme activity associated with the coated tubes was measured to determine fibronectin concentration.

Main Results:

• The developed assay demonstrated a reliable quantification range of 0.5-20 microgram/ml for fibronectin.
• The mean plasma fibronectin concentration in female patients was determined to be 270 microgram/ml (SD 50 microgram/ml, n=22).
• Denatured fibronectin showed minimal activity, indicating assay specificity, and cross-reacting antigens were detected in rat and guinea pig plasma.

Conclusions:

• The competitive enzyme immunoassay provides a sensitive and specific method for fibronectin quantification in plasma.
• The assay is suitable for clinical applications and research involving fibronectin level determination.
• The method also shows potential for detecting fibronectin-related antigens across different species.