I have the following questions please:

1. Is the Roche Cobas 6000 a 4th Gen duo test or does it only test for AB?

2. How accurate is my negative result at 42nd day if it was a 4th gen test?

3. Is it possible that they are conducting 3rd gen tests on this machine?

4. How accurate are these tests and is it possible they give inaccurate results if the machine isn’t calibrated or if it isn’t operated properly?

Thanks!

1. The definition of "4th generation" or "duo" is that the test is for both antigen and antibody.

2. 100% conclusive.

3. No. Each test comes with its own automated machinery. There is no way they ran an antibody-only test.

4. The automation and calibration systems are essentially foolproof. You can rely entirely on your negative test result.

HHH, MD

I just want to make sure that the lab has conducted a 4th generation test because the test name does not say Ab/AG or DUO. The test only says "Anti-HIV 1/2".

I asked the lab on their helpline but there person on the line didnt seem to know.

So just checking to make sure that Roche Cobas is a 4th generation machine so I can consider my result conclusive. 

Lastly, I just want to ask you regarding Raegants used for these tests, is it possible that the lab is conducting the test without using raegants or the raegants are not stored at proper temperature.

Thanks!

I'm not an expert in the detailed technology of the tests, but I have never heard of a problem with reagent stability.

Thank you for the reply. I apologize for being repetitive. 

I spoke to the lab and they confirmed the test was run on a e601 analyzer.  They also explained that raegants are stored properly and that I should not worry about that (they import their raegants from Abbott USA). 

Just want to ask you following please:

1. Given that the test was run on a e601 analyser and that the test they ran was a Combo test, is this considered a 4th gen test?

2. I saw that the e601 is not FDA approved, apparently e602 analyser is the approved module for Roche. Does it matter? Roche website says that Combo is available on both e601 and e602.

3. If it was an antibody only test on the ECLIA method, would it be accurate at 6 weeks? 

Thanks Doctor. You have been a great help!

2. To my knowledge, this does not matter. I'm not aware that FDA certification is required for such analyzers.

3. The third generation antibody tests are nearly conclusive at 6 weeks (~98-99%), but require 8 weeks for conclusive results.

That completes the two follow-up exchanges included with each question and so ends this thread. Sorry I couldn't answer some of your follow-up questions. But the important thing is the overwhelming evidence you do not have HIV. Once you have confirmed the test results, and assuming they indeed are negative, please don't return with more quesitons about it. Repeat questions about the same situation are discouraged; having already had two, no more should be needed. if negative at the appropriate time(s) after exposure, we would only confirm that the negative result is reliable and proves you don't have HIV. However I do hope the discussions have been helpful. Best wishes and stay safe.