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Fecal Occult Blood (FOB) Test Cassette (Colloidal Gold)


Fecal Occult Blood (FOB) Test Cassette (Colloidal Gold) is a rapid chromatographic immunoassay for the qualitative detection of human occult blood in feces by professional laboratories or physician’s offices. It is useful to detect bleeding caused by a number of gastrointestinal disorders, e.g., diverticulitis, colitis, polyps, and colorectal cancer.

Storage and Stability

  • Store at 4 to 30°C in a dry place and avoid direct sunlight. Do not freeze. It is valid for 24 months from the date of manufacturing.

Assay Procedure

1. Bring the pouch to room temperature before opening it. Remove the test cassette from the sealed pouch and use it as soon as possible.

2. Holding the sample collection tube upright, carefully take off the tip of the collection tube, transfer 3 drops (approximately 100μl) to the sample well of the cassette, and then start the timer.

3. Wait for the colored line(s) to appear. Read results at 15 minutes. Do not interpret the result after 20 minutes.

Notes: Applying a sufficient amount of specimen is essential for a valid test result. If migration (the wetting of membrane) is not observed in the test window after one minute, add one more drop of the specimen to the specimen well.


Results Interpretation

  • Negative: The control line is the only visible line on the test device. This indicates a negative result.

  • Positive: The presence of two color lines (“T” line and “C” line) within the result window, no matter which line appears first, indicates a positive result.

  • Invalid: If the “C” line (control) is not visible within the result window after performing the test, the result is considered invalid. The directions may not have been followed correctly or the test may have deteriorated. It is recommended that the specimen be re-tested.


  • The kit is used for auxiliary diagnosis of FOB. Any positive sample must be confirmed with other available methods (such as EIA or RIBA). Negative samples generally does not require further confirmation.

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