A simple & rapid Dot-ELISA dipstick technique for detection of antibodies to Entamoeba histolytica in amoebic liver abscess

A rapid dipstick Dot-ELISA haJ been developed for detection of antibodies against E. his­ tolytica employing soluble fraction or the sonicate prepared from axenlcally grown E. his­ tolJ·tica NIH : 200. The antigen was bnmobllized on nitrocellulose paper Hxed to a plastic strip, at a t'OIICefttlatlon of 2. S p.g (Protein content) which gave optimal results. The assay deTefoped was 8!11lble with test Hn1Dt dlluted 1:200. s p.l or test serum was adequate for the assay. MO!It or the antJamoeblc antibodies In the sera of patients with amoebic liver absc:as (ALA) were found to be or lgG type. Protein-A conjugJlted to HRPO was employed lor tbe test and 4-diJoro...l-naphthol plus H 20 2 was used as substrate. A clear blue dot against whHe background Indicated the presence or antlamoebic antibodies In the test Sft'IIJII. The test could be completed In 35 min. This dipstick Dot-EIA was'evaluated In another Independent laboratory on 101 ftniDl samples of which 40 sera were from micro­ biologically and dfnbiJy conftrmed patients or ALA. Thirty nine of these samples were diagnosed correctly by the present tedmJqae. None or the 25 healthy controls were positive In the llSSay. The test was also negative In subjects with giardiasis, hepatomegaly, peptic olcen aDd pyrexia olamknown origin. It was positive only In 8 or 25 'patients of amoebic colitis. Its comparadve merits wltb previously available lab assays for the diagnosis or ALA 11ft dlsansd.