In the anti-double-stranded DNA procedure, what antigen is most commonly utilized?

The use of Crithidia luciliae in the anti-double-stranded DNA procedure is significant because it is a key indicator in the diagnosis of systemic lupus erythematosus (SLE). Crithidia luciliae is a flagellated protozoan, and its kinetoplast contains a circular DNA structure that resembles double-stranded DNA. This makes it an excellent substrate for detecting antibodies against double-stranded DNA in patient's serum, which is a specific diagnostic marker for SLE.

When serum containing anti-dsDNA antibodies is introduced to the Crithidia luciliae, the antibodies will bind to the kinetoplast DNA, facilitating visual detection through fluorescence microscopy or other techniques. This specificity enhances the accuracy of the test, making it a cornerstone in the immunological evaluation of suspected lupus patients.

The other antigens mentioned, such as Micrococcus luteus, Bordetella pertussis, and Staphylococcus epidermidis, are not relevant to the detection of anti-double-stranded DNA antibodies. These organisms are not associated with the specific autoimmune responses involved in lupus and therefore do not serve as effective antigens in this context. Their use in serological testing is generally towards other infections rather than in the assessment of autoimmune diseases like