Sm IgG EULISA

Add to my product list
The EULISA Sm IgG is a fast and reliable ELISA kit for determination of Sm-antibodies. These antibodies are highly specific for systemic lupus erythematosus (SLE). Since the sensitivity is limited, with a prevalence <30%, they represent one parameter in a multi criterion diagnostic process.

Product code
213396
Format
ELISA
Tests
Break apart micro titration strips (12x8) 96 wells
Calculation
Qualitative and quantitative
Antigen
Mixture of Sm-D polypeptides
Units
U Sm-Ab/mL
Calibrators
6
Range
0-40 U Sm-Ab/mL
Incubation time
30+30+30 min
Detection system
HRP/450 nm
Availability
CE marked. Not for sale in US

Intended use

Enzyme immunoassay for the detection of autoantibodies IgG against Sm.

 

Background

Uracil-rich, small nuclear RNAs (U-snRNA) are physiologically complexed with proteins to form ribonucleoprotein particles (U-snRNP) which are involved in the splicing process of pre-mRNA. Different complexes (U1-U6) can be distinguished according to the participating RNA; their protein components are in part common, in part different.

Sm auto-antibodies (so-called according to the first described patient Smith) are directed against those proteins that are common to most RNPs. The largest ones, B, B' and D (28, 29 bzw. 16 kDa), are the most important antigenic targets. Sm antibodies are highly specific for systemic lupus erythematosus (SLE) but exhibit only limited sensitivity (prevalence < 30%).

Technical information

The EULISA Sm IG is intended for the quantitative or qualitative determination of IgG antibodies in human serum, directed against Sm. The immobilised antigen is a mixture of the most abundant Sm-D polypeptide subtypes, all of them isolated from bovine thymus. Sm-B/B’ polypeptides are absent in the preparation since autoantibodies against the U1-RNP specific proteins A and C (primarily indicative for mixed connective tissue disease (MCTD)) tend to cross-react with these auto-antigens.

The test is fast (incubation time 30 - 30 - 30 minutes) and flexible (break apart wells, ready-to-use reagents). Six calibrators allow quantitative measurements; a negative and a positive control to check assay performance.

Kit components and storage of reagents

Contents of the kit

  1. 1 microwell plate, coated with Sm-specific antigens and hermetically packed in a foil laminate pouch together with a desiccant bag.
  1. Sample buffer, 100 mL, ready-to-use, orange coloured.
  1. Wash buffer, 100 mL, 10 x-concentrate, blue coloured.
  1. 6 calibrators, 2.0 mL each; 0, 0.40, 1.2, 4.0, 12 and 40 U Sm antibodies IgG/mL, ready-to-use, gradually blue coloured.
  1. Negative and positive control, 2.0 mL each, ready-to-use, green and red coloured, respectively.
  1. Anti-human IgG HRP conjugate, 14 mL, ready-to-use, red coloured.
  1. Substrate solution, 14 mL, ready-to-use, colourless.
  1. Stop solution (0.5 M H2SO4), 14 mL, colourless, ready-to-use.
  1. Directions for use
  1. Lot-specific certificate of analysis

All kit components are stored at 2 - 8°C.