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Test ID FRGAM Rheumatoid Factor (RF); IgG, IgA and IgM

Specimen Required

Container/Tube: Red-top tube

Acceptable: SST tube

Specimen Volume: 1.50 mL

Collection Instructions: Draw blood in a plain, red-top tube(s) or a serum-gel tube(s). Spin down and send 1.50 mL of serum refrigerated in a plastic vial.

Method Name

Enzyme Linked Immunosorbent Assay (ELISA)

Reporting Name

Rheumatoid Factor IgG, IgA, IgM

Specimen Type


Specimen Minimum Volume

0.50 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 5 days
  Frozen  365 days
  Ambient  5 days

Reference Values

Rheumatoid Factor (RF) levels IgG:

Negative: <20 EU/mL

Borderline/Equivocal: 20-25 EU/mL

Positive: >25 EU/mL


Rheumatoid Factor (RF) levels IgA:

Negative: <20 EU/mL

Borderline/Equivocal: 20-25 EU/mL

Positive: >25 EU/mL


Rheumatoid Factor (RF) levels IgM:

Negative: <10 IU/mL

Borderline/Equivocal: 10-12.5 IU/mL

Positive: >12.5 IU/mL

Day(s) Performed

Once per week

Report Available

7 to 18 days

Performing Laboratory

IMMCO Diagnostics, Inc.

Test Classification

This test has been developed and performance parameters have been validated by IMMCO Diagnostics, Inc. This test has not been approved by the U.S. Food and Drug Administration (FDA); however, US FDA approval is not required for clinical use. It is not intended that clinical diagnosis and patient management decisions be made using these results alone. This test has been validated using serum samples. The manufacturer has not determined the efficacy of this when performed on CSF, plasma, joint or pleural fluid specimens. The performance characteristics of this test were determined by IMMCO Diagnostics Inc.

CPT Code Information

86431 x 3

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FRGAM Rheumatoid Factor IgG, IgA, IgM Not Provided


Result ID Test Result Name Result LOINC Value
Z5623 Rheumatoid Factor IgG 33314-6
Z5624 Rheumatoid Factor IgA 33313-8
Z5625 Rheumatoid Factor IgM 11573-3