The Lyme IgG or IgM 31kDa Epitope** test is a qualitative immunoblot assay that determines whether the 31kDa band present on a Lyme Western Blot IgG or IgM is due to B. burgdorferi specific antibody or not.

Reference Range

Negative - No visible bands present

Clinical Significance

It is known that Western blots, especially IgM, can give false positive results with some viral and bacterial infections. This test determines whether the band present at position 31 kDa on the IGeneX Lyme Western Blot IgM is specific for B. burgdorferi. Serum from the patient is tested against a Western Blot strip with fixed B. burgdorferi specific recombinant antigen fragments.


  1. This test is only performed on samples that are previously tested by Lyme Western Blot IgM at IGeneX and have a band at 31kDa position on the blot.
  2. Positive results for the 31kDa band may be present after vaccination in uninfected persons.
  3. IGeneX interpretation is based on internal validation studies.
  4. The results of this test must be interpreted in relation to patient’s clinical history, epidemiological data, stages of disease, clinical symptoms or other laboratory results.

Special Instructions This test is not yet available for NY residents.

Ordering Information

Specimen Serum sample positive for 31 kDa antigens on the IGeneX Lyme IgM Western blot.

Test Offered

Test# 488 31 kDa Epitope Test IgM CPT Code 86617
Test# 489 31 kDa Epitope Test IgG CPT Code 86617

**Test/Panels are not yet available for New York Residents