MORL Screening Methodology
The C3b deposition assay (C3bDA) quantifies complement-mediated C3b deposition on cell surfaces following activation of the alternative pathway (AP). In brief, patient serum is diluted in a buffer conducive to AP activation and applied to cultured MES-13 cells, which are then incubated at 37°C for 20 minutes. C3b deposition on cell surfaces is visualized using Alexa-488 labeled anti-C3 antibody.
Indications for Testing
- 1ml frozen serum
- Serum samples must be frozen to below -80°C immediately after separation from cells and shipped on dry ice. These samples remain viable for at least six months when stored at -80°C.
- All serum samples MUST be processed and frozen down to -80°C immediately after collection
- Labeled with the sample type AND patient’s name, DOB, MRN and sex
- Cryovials should be put in zip lock bags and completely covered in dry ice to keep the sample frozen until it arrives in the lab
- Shipped overnight on at least 5 lbs of dry ice
- Shipping and receiving dock closed on weekends and holidays
- Deliveries accepted Monday - Friday
If samples arrive thawed they will be REJECTED.
The C3b deposition assay (C3bDA) quantifies complement-mediated C3b deposition on cell surfaces following activation of the alternative pathway (AP). In brief, patient serum is diluted in a buffer conducive to AP activation and applied to cultured MES-13 cells, which are then incubated at 37°C for 20 minutes. C3b deposition on cell surfaces is visualized using Alexa-488 labeled anti-C3 antibody.
Quick Facts
- CPT code: 86162
- Test code: 01C3BDA
- Turnaround time: 4 weeks
- Cost: $300
Background Knowledge
Thrombotic microangiopathies (TMA) include a spectrum of life-threatening multi-systemic disorders characterized by microvascular thrombosis, consumptive thrombocytopenia, and microangiopathic hemolytic anemia, often culminating in renal failure, cerebral ischemia, and end-organ damage. While TMAs can be the result of multiple factors such as infections, cancers, pregnancy, drugs, trauma, malignant hypertension, and cobalamin deficiency, complement-mediated TMAs are driven by the hyperactivity of the complement alternative pathway on the cell surface. The C3b deposition assay detects C3b deposition resulting from fluid-phase complement dysregulation.
The Clinical Diagnostics Service of the Molecular Otolaryngology & Renal Research Laboratories is a CLIA-approved, Joint Commission-accredited diagnostic laboratory.