1
Medical Questions > Womens Health > Sexual Health - Women Forum

hiv rapid immunocromatographic test result - why is there a time

Must Read
Do you know what causes HIV? Get started by learning the facts on HIV and AIDS here....
Do you know what puts you at high risk of HIV? Debunk the myths and get the facts of HIV risk factors here....
Can you identify early HIV symptoms. Learn what to look for and when to seek medical help as we review symptoms of HIV here....
User Profile
why we cannot read the result of hiv rapid immunocromatographic test after specified time (end-reading point) and the result obtained after this specified time is valid or not.What is the actual result if it is negative during the specified time and appearing two imcomplete dark bands after 7 hours.


Did you find this post helpful?
|

User Profile
replied November 28th, 2007
Sexual Health - Women Answer A3322
The basic principle behind an HIV rapid immuno-chromatographic test is that HIV-antigens placed on the test-strip will react with Anti-HIV antibodies (if there are any) from the blood. That reaction becomes visible as a colored line next to the control line. The reaction between antigens and antibodies (if there are any) requires 5-15 minutes to become visible depending upon the concentration of the antibodies in the blood (if present). However, if the test does not show a control line, the result is not valid.

The producers of the IV rapid immuno-chromatographic test say that the resulting interpretation after 20 minutes is also not valid unless the room temperature is under 15oC. In your case the test result after 20 min. was negative but became “positive” after 7 hours. That “positive” result is not valid. Your test result was NEGATIVE.

I assume that the reason the test results are not valid after 20 minutes is that after time, another factor in the the blood can precipitate and create a line that can be similar to the line created by antibody-antigen reaction. Further, the line created by an antibody-antigen reaction can also disappear in time because links between antigens and antibodies can get weak. But this hypothesis has not been confirmed by the manufacturers.


hiv rapid immunocromatographic test result - why is there a time limit?


|
Did you find this post helpful?
This question has been answered by the doctor. This topic is now open for public discussion, however no comments below this point will be answered by a doctor.
DISCLAIMER: "Ask a Doctor" questions are answered by certified physicians and other medical professionals. For more information about experts participating in the "Ask a Doctor" Network, please visit our medical experts page. You may also visit our Sexual Health - Women , for moderated patient to patient support and information.

The information provided on eHealth Forum is designed to improve, not replace, the relationship between a patient and his/her own physician. Personal consultation(s) with a qualified medical professional is the proper means for diagnosing any medical condition.