Immunoassay hemagglutination assay

Diagnostic procedures include dark-field microscopy12, non-treponemal exams10 (i.e., the Venereal Disease Laboratory and the rapid plasma reagin test), and treponemal exams (i.e., enzyme immunoassay, the T. pallidum hemagglutination test, the fluorescent treponemal antibody test, and the enzyme-linked immunosorbent assay). 

Methods for detection of anti-dsDNA include immunofluorescence, hemagglutination, radioimmunoassay (RIA), and enzyme-linked immunoassay (ELISA). Different methods may result in discrepant results due to the heterogeneous nature of the antibodies (S20). Numerous studies that compare methods conclude that no single test is perfect. It may be necessary to combine different methods for both higher sensitivity and higher specificity. The most commonly used methods for detecting anti-dsDNA are the CLIF test, the Farr assay, and the ELISA test. 

Cost Effectiveness. As with the other advantages of immunochemical analysis, cost may be quite variable. Reagent costs for several automated systems have been estimated at under 1.25 per sample. The cost is obviously much lower for less sophisticated assay systems, especially if some reagents are prepared in house. A major consideration is the expense of new instrumentation. For dedicated or automated instrumentation for either RIA or ELISA procedures, the cost may be 50-100,000. However, most analytical laboratories already have the basic instrumentation needed for immunoassays. Moderate sensitivity can be obtained through the use of numerous procedures such as radial immunodiffusion and hemagglutination. These procedures require no expensive equipment or reagents and they may be very useful in areas where equipment acquisition or maintenance is a problem. 

ACE = angiotensin-converting enzyme ANA = antinuclear antibody ANCA = antineutrophil cytoplasmic antibody BUN = blood urea nitrogen CBC = complete blood count ELISA = enzyme-Mnked immunoassay assay ESR = erythrocyte sedimentation rate FTA-ABS = fluorescent treponemal antibody absorption HLA = human lymphocyte antigen MHA-TP = micro-hemagglutination-7re/ OMew pallidum-, PPD = purified protein derivative RPR = rapid plasma reagin VDRL = venereal disease reference laboratory. 

The first immunological assay for TSH was based on the cross-reaction of human and bovine TSH in a hemagglutination inhibition test however, this method was too insensitive for chnical purposes. Immunoassay measurement of serum TSH concentration did not become a routine test until the purified pituitary hormone became available for immuniz,ation and iodination. 

Wide and his colleagues (W5, W7) were the first to apply the technique of hemagglutination-inhibition to the estimation of urinary LH. They found that some antisera raised against HCG were incapable of distinguishing between HCG and LH, and, accordingly, they were able to establish an assay system for LH using an antiserum raised to HCG and HCG-coated red blood cells. Taymor (T2) used a similar system to assay human urinary LH. He also employed an HCG antiserum and latex particles coated with this hormone the system was specific in that a cross reaction with ovine LH was not observed however, its specificity with respect to FSH was not reported. Taymor (T2) found it necessary to extract LH from urine prior to immunoassay. For this purpose he preferred precipitation with acetone to treatment with alcohol, since trace amounts of the latter interfered with the antigen-antibody reaction. 

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