SUMMARY AND EXPLANATION THE TEST
Cholera is an acute infectious disease that is characterized by massive loss of body fluids and electrolytes through severe diarrhea. The etiological agent of cholera has been identified as Vibrio cholerea (V. Cholerae), a gram negative bacterium, which is generally transmitted to humans via contaminated water and food.
The species V. Cholerae is divided into several serogroups on the basis of O antigens. The subgroups O1 and O139 are of special interest because both can cause epidemic and pandemic cholera. It is critical to determine as quickly as possible the presence of V. cholerae O1 and O139 in clinical specimens, water, and food so that appropriate monitoring and effective preventive measures can be undertaken by public health authorities.
The Cholera Ag Rapid Test can be used directly in the field by untrained or minimally skilled personnel and the result is available in less than 10 min, without cumbersome laboratory equipment.
PRINCIPLE
The Cholera Ag Rapid Test is a lateral flow chromatographic immunoassay. The test cassette consists of: 1) a burgundy colored conjugate pad containing monoclonal anti-V. Cholera O1 and O139 antibodies conjugated with colloid gold (O1/O139-antibody conjugates) and rabbit IgG-gold conjugates, 2) a nitrocellulose membrane strip containing two test band (1 and 139 bands) and a control band (C band). The 1 band is pre-coated with monoclonal anti-V. Cholera O1 antibody. The 139 band is precoated with monoclonal anti-V. Cholera O139 antibody. The C band is pre-coated with goat anti-mouse IgG antibody.
When an adequate volume of test specimen is applied into the sample well of the test cassette, the specimen migrates by capillary action across the cassette. V. Cholera O1/O139 antigen if present in the specimen will bind to the corresponding O1/O139-antibody gold conjugate. This immunocomplex is then captured on the membrane by the pre-coated anti-V. Cholera O1/O139 antibody, forming a burgundy colored test band, indicating a Cholera O1/O139 positive test result. Absence of the test band suggests a negative result.
The test contains an internal control (C band) which should exhibit a burgundy colored band of the immunocomplex of goat anti-mouse IgG/ mouse IgG-gold conjugate regardless of the color development on the test band. Otherwise, the test result is invalid and the specimen must be retested with another device.
