A microELISA Raji cell assay to detect immune complexes

Area of Science:

• Immunology
• Biochemistry
• Assay Development

Background:

• Immune complexes play a role in various autoimmune diseases.
• The standard Raji cell assay is a common method for detecting immune complexes.
• The standard Raji cell assay involves radioactivity, posing safety concerns.

Purpose of the Study:

• To adapt the Raji cell assay for immune complex detection into a microtiter enzyme-linked immunosorbent assay (ELISA) format.
• To evaluate the sensitivity and reliability of the modified Raji micro-ELISA.
• To offer a safer and simpler alternative to the standard Raji cell assay.

Main Methods:

• Raji cells were immobilized onto microplate wells.
• Immobilized Raji cells were incubated with serum samples or aggregated human IgG.
• Bound immune complexes were detected using horseradish peroxidase-conjugated anti-human IgG.

Main Results:

• A linear correlation was observed between the amount of aggregated IgG and optical density readings.
• The assay demonstrated high sensitivity, detecting less than 2 micrograms/ml of aggregated IgG.
• Results from the Raji micro-ELISA were comparable to those obtained with the standard Raji cell assay when tested with human serum.

Conclusions:

• The Raji micro-ELISA is a simplified, reliable, and radioactivity-free method for detecting immune complexes.
• This assay offers a practical alternative to the traditional Raji cell assay for clinical and research applications.
• The enhanced Raji micro-ELISA facilitates immune complex detection with improved safety and ease of use.