Rheumatoid Factor (RF) Test

Rheumatoid Factor (RF) Test

Aim

Determination of RF or Rheumatoid Factor antibody in serum.

Principle

Rheumatoid factors are a group of antibodies directed to the determinants in the Fc portion of the ImmunoglobulinG molecule (IgG). Presence of Rheumatoid factor in serum indicates the condition of Rheumatoid Arthritis and thus it is used as an aid in the Diagnosis of Rheumatoid Arthritis.  Rheumatoid factors are also  found in a number of Rheumatoid disorders such as Systemic Lupus Erythematosus and Sjogrens syndrome as well as in non Rheumatic conditions.  

RF Latex kit is a rapid agglutination procedure for the detection and semi quantitation of Rheumatoid Factors.  The antigen is a latex particle suspension coated with human gamma globulin.  Antigen will agglutinate in presence of Rheumatoid factors in the patient serum.

Materials required

·         RF Latex Antigen

·         RF Positive control – human pooled serum – 1 x 0.5 ml – sample A

·         RF negative control – human pooled serum – 1 x 0.5 ml – sample B

·         Physiological Saline Buffer Concentrate – 1 x 5 ml

·         Reaction slides

·         Applicator sticks

·         Serum Droppers

·         Rubber teat

Procedure

1.      All the reagents and the samples were allowed to reach room temperature and mixed well

2.      One drop of serum sample was placed on the slide with the help of a disposable serum dropper (Sample A and B)

3.      One drop of RF Latex antigen was added to the above drops and mixed using an applicator stick

4.      The slide was rocked gently to and fro for 2 minutes and it was examined for agglutination under light

Result

The appearance of agglutination indicates the presence of specific antibody (RF) in the serum sample.