Ro/SS-A Antigen (Ro-60/SS-A)

The (Ro) SS-A antigen is comprised or an acidic 60kD protein that may also be associated with a RNA ranging in size from 80 to 112 bases (1). The antigenic activity of the (Ro) SS-A antigen appears to be independent of the RNA since the precipitin activity remains after treatment with RNase or separation from the RNA (1). Anti-(Ro) SS-A autoantibodies were described originally as precipitating autoantibodies in sera of Sjogren's Syndrome and Systemic Lupus Erythematosus patients. The presence of autoantibodies against the (Ro)SS-A antigen may be used as a diagnostic aid. Elevated levels of Anti-(Ro) SS-A have been detected in as high as 96% of Sjogren's Syndrome patients (2), 49% of patients with Systemic Lupus Erythematosus (2), 83% of mothers of infants with isolated complete congenital heartblock or Neonatal Lupus Dermatitis, and over 75% of patients with Subacute Cutaneous Lupus. Recently, a strong correlation between low positive levels of Anti-(Ro) SS-A and subdinical dry eyes or mouth was found in a substantial portion of an elderly population (3). In addition, it has been shown that 70% of patients with (Ro) SS-A precipitating antibodies also have rheumatoid factor (4). The titer of rheumatoid factor and the concentration of Anti-(Ro) SSA have been closely correlated in Primary Sjogren's Syndrome (4). Recent developments in ELISA methodology have increased the sensitivity and the ability of the diagnostician to quantitate patient antibody titers.\n\nUnit Definition: One unit of activity is the amount of antigen that will generate an absorbance of 1.2 when assayed using standard procedure for ELISA. Activity will vary with assay conditions/ protocols.\n\nApplication: Suitable for use in ELISA. Other applications not tested.\n\nRecommended Dilutions:\nOptimal dilutions to be determined by researcher.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage, aliquot and store at -20 degrees C. Aliquots are stable for at least 6 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.\n\nAlso Available:\nR2997: Ro/SS-A Antigen Pab Hu xHu\nR2997-04: Ro/SS-A Antigen

Prices direct from United States Biological

Quick response times

Exclusive Biosave savings/discounts

SPECIFICATIONS

Catalog Number

R2997-04

Size

100U

Applications

ELISA

Form

Supplied as a liquid in 0.01M Tris, 0.5M sodium chloride, 0.02% sodium azide.

Purity

Purified by immunoaffinity chromatography. Other antigens (Sm, RNP, Scl-70, Jo-1) are not detected with ELISA assays. Homogeneity is verified by SDS PAGE.

References

1. Mamula MJ, Fox OF, Yamagata H, and Harley JB. \"The (Ro) SS-A Autoantigen as an Immunogen Some Anti-(Ro) SSA Antibody Binds IgG.\" J of Exp Med Vol 86: pg 1889-1901. 2. Rader MD, O'Brien C, Liu Y, Harley JB, and Reichlin M. \"Heterogeneity of the (Ro) SSA Antigen, Different Molecular Forms in Lymphocytes and Red Blood Cells.\" J. Clin. Invest Vol 83: 1989, pg 1293-1298. 3. Harley JB, Kaine JL, Fox OF, Reichlin M, Gruber B. \"Ro SSA Antibody and Antigen in Cogenital Complete Heart Block ((Ro) SSA and Heart Block).\" University of Oklahoma, Health Science Center, Arthritis and Immunology Program, Oklahoma Medical Research Foundation, pg 1-16. 4. Harley JB, Alexander EL, Bias WB, Fox OF, et al. \"Anti-(Ro) SSA and Anti-(La) SSB in Sjogren's Syndrome.\" Dept of Med, University of Oklahoma, Health Science Center, Arthritis and Immunology Program, Oklahoma Medical Research Foundation, pg 1-35.