Lateral Flow Assay AllTest Salmonella Typhi Antigen Rapid Test Cassette ISTY -602

Lateral Flow Assay AllTest Salmonella Typhi Antigen Rapid Test Cassette ISTY -602

Applications:

The S.typhi Antigen Rapid Test Cassette (Feces) is a rapid chromatographic immunoassay for the qualitative detection of Salmonella typhi antigens in human feces specimens to aid in the diagnosis of Salmonella typhi infection.

Description:

Typhoid fever is a life threatening illness caused by the bacterium Salmonella typhi, and was observed by Eberth (1880) in the mesenteric nodes and spleen of fatal cases of typhoid fever¹. The infection is acquired typically by ingestion. On reaching the gut, the bacilli attach themselves to the epithelial cells of the intestinal villi and penetrate to the lamina and submucosa. They are then phagocytosed there by polymorphs and macrophages. The ability to resist intracellular killing and to multiply within these cells is a measure of their virulence. They enter the mesenteric lymph nodes, where they multiply and, via the thoracic duct, enter the blood stream².

The S. typhi Antigen Rapid Test Cassette (Feces) is a rapid chromatographic immunoassay for the qualitative detection of Salmonella typhi antigens in human feces specimens, providing results in 5 minutes. The test utilizes antibodies specific for Salmonella typhi antigens to selectively detect S. typhi antigens in human feces.

How to use?

Allow the test, specimen, buffer and/or controls to reach room temperature (15-30°C) prior to testing.

• To collect fecal specimens:

Collect sufficient quantity of feces (1-2 mL or 1-2 g) in a clean, dry specimen collection container to obtain maximum antigens (if present). Best results will be obtained if the assay is performed within 6 hours after collection. Specimen collected may be stored for 3 days at 2-8℃ if not tested within 6 hours. For long term storage, specimens should be kept below -20℃.

• To process fecal specimens:

• For Solid Specimens:

Unscrew the cap of the specimen collection tube,then randomly stab the specimen collection applicator into the fecal specimen in at least 3 different sites to collect approximately 50mg of feces (equivalent to 1/4 of a pea). Do not scoop the fecal specimen.

• For Liquid Specimens:

Hold the dropper vertically, aspirate fecal specimens, and then transfer 2 drops (approximately 100μL) into the specimen collection tube containing the extraction buffer.

Tighten the cap onto the specimen collection tube, then shake the specimen collection tube vigorously to mix the specimen and the extraction buffer.

• Bring the pouch to room temperature before opening it. Remove the test cassette from the foil pouch and use it within one hour. Best results will be obtained if the test is performed immediately after opening the foil pouch.
• Hold the specimen collection tube upright and open the cap onto the specimen collection tube. Invert the specimen collection tube and transfer 3 full drops of the extracted specimen (approximately 120μL) to the specimen well (S) of the test cassette, then start the timer. Avoid trapping air bubbles in the specimen well (S). See illustration below.
• Read results at 5 minutes after dispensing the specimen. Do not read results after 15 minutes.

Note: If the specimen does not migrate (presence of particles), centrifuge the extracted specimens contained in the extraction buffer vial. Collect 120μL of supernatant, dispense into the specimen well (S) of a new test cassette and start afresh following the instructions mentioned above.

INTERPRETATION OF RESULTS

(Please refer to the illustration above)

POSITIVE:* Two lines appear. One colored line should be in the control line region (C) and another apparent colored line should be in the test line region (T).

*NOTE: The intensity of the color in the test line region (T) will vary depending on the concentration of S. Typhi antigen present in the specimen. Therefore, any shade of color in the test line region (T) should be considered positive.

NEGATIVE: One colored line appears in the control line region (C). No line appears in the test line region (T).

INVALID: Control line fails to appear. Insufficient specimen volume or incorrect procedural techniques are the most likely reasons for control line failure. Review the procedure and repeat the test with a new test. If the problem persists, discontinue using the test kit immediately and contact your local distributor.