Typhoid Antibody Test

Typhoid Antibody Test

Typhoid Antibody Test

The typhoid test is a two-site sandwich immunoassay based on the principle of immuno-chromatography on a membrane. Each card test contains a strip composed with absorbent pad, nitrocellulose membrane, conjugate pad and sample pad. The nitrocellulose membrane is coated with test line proteins at ‘M or ‘1’ region & at ‘G; or ‘2’ region and control line protein at ‘C’ region. When a specimen containing antibody of Salmonella is applied along with assay buffer on the sample pad area, it reacts with colloidal gold conjugated with recombinant protein of Salmonella and makes an immune complex. This complex moves further chromatographically and reacts with the proteins coated on the nitro cellulose membrane leading to the formation of colored band at the (M or 1 & G or 2) region. The appearance of colored band in the specific region is considered as positive result for that particular antibody. If the specimen does not contain any salmonella / typhoid antibodies, no colored line will appear in either of the test line (M or 1 & G or 2) regions, indicating a negative test result. To serve as a procedural control, a colored line will always appear in the control line region confirming that the test has performed properly. Typhoid test is stable for 24 months from date of manufacturing if stored at 2-40°C.