Gravindex is an agglutination inhibition test performed on a urine sample to detect pregnancy.[1] It is based on double antigen antibody reaction. The test detects the prevention of agglutination of HCG-coated latex particles by HCG present in the urine of pregnant women.[2]
| Gravindex | |
|---|---|
| Purpose | pregnancy test |
Procedure and results
editKits commercially available contain two reagents; one is a suspension of HCG-coated latex particles, and the other is a solution of HCG antibodies. One drop of the urine is mixed with one drop of antibody solution for one minute on a black glass slide. One drop of the HCG-coated latex particles is added to the slide and left for one minute.
- If the level of HCG is too low, the antibodies will remain to agglutinate the HCG-coated latex particles. If agglutination occurs, the subject is not pregnant.
- If the level of HCG is high, the HCG will bind to the antibodies, and thus no agglutination with the HCG-coated latex particles occurs. If no agglutination occurs, the subject is pregnant.
References
edit- ^ MCH Research Series. Health Services Administration, Bureau of Community Health Services. 1974. pp. 8–9.
- ^ Khurana, Indu; Khurana, Ayushi (2022-07-06). Concise Textbook of Human Physiology - E-Book. Elsevier Health Sciences. p. 422. ISBN 978-81-312-6474-4.