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Western Blot, PCR, and Elisa?

Western Blot, PCR, and Elisa?

Hello,

I have had a PCR test done and it was negative. I found out that I had taken the wrong test though, as it said it was for people with recent 3 months or less exposure. Naturally I felt that my result was incorrect and started to panic, since I am well past a few years since my exposure.

Then I had a Western Blot done, and it was negative. Then I read that Western Blots are only good if they were accompanied with an Elisa. So I panicked again, thinking my results were incorrect.

So now I am here, to ask all of you, which test is best? I'd like to be tested for both strains of HIV, I think in medical terms it's HIV1/O/2. An Elisa test is not available where I buy testing at (prepaid lab) and so these tests are the ones available:
http://www.prepaidlab.com/Human-Immunodeficiency-Virus-1/O/2-HIV-1/O/2-Antibody-With-Ref.html
http://www.prepaidlab.com/HIV-STD-Tests/HIV-SCREEN-Western-Blot-Confirmation-on-Positives-Human-Immuno.html?keyword=hiv

Which one is best out of these two? Does the PCR still count? and if I get a negative on the Western blot without an Elisa am I still negative? Which test all in all are better? Should I go out of my way for an Elisa test? Which one is most accurate, out of all the tests out there?

Don't tell me I don't need another test, I am a hypochondriac and I need one last test for some peace.

Thank you all, I have been living in sheer terror everyday and I want to breathe without worry.
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15 Comments Post a Comment
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1563685_tn?1310405954
PCR isn't appropriate for testing HIV, but ELISA is.

If the ELISA test is done 3 months post-exposure and the result comes out negative, then you're conclusively negative. But if positive, you'll be referred to Western Blot as a CONFIRMATIVE test. If the WB result comes out negative but the previous ELISA positive, you conclusively don't have HIV.

So the appropriate one is ELISA first and IF required (read above) then followed up with Western Blot, but not other way around.
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Avatar_m_tn
What's the difference, if you can explain to me. If Elisa must come first, and it technically doesn't matter if it's negative or positive because I'll end up having to take the western blot anyway?

My western blot was negative, that should mean I was negative right? I wouldn't need an Elisa because the western blot is confirmative and it's used as a "final" say anyway?
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Avatar_m_tn
Basically this is my question:

Can I take 2 Western Blot HIV tests and rely on them?

The site where I get my HIV testing from doesn't have the Elisa test as an option. I know this test usually comes first.

Instead I took 2 Western Blot tests for HIV and they were negative. Because I didn't take the Elisa, can I rely on the Western Blot results?

I really need help...
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Avatar_m_tn
Please someone answer my question, I need to make a decision of what test to take by tomorrow! Or if I even need to at all!?

Are 2 negative Western Blots good enough to tell me or do I really need an Elisa??
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1563685_tn?1310405954
It would be better when there were two different tests to give you a final judgement, and ELISA would better come first, WB serves as a CONFIRMATIVE test.

So ELISA, and then WB when required (that is, when the ELISA test result comes out positive).
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1563685_tn?1310405954
Btw, why do you need to get tested?
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1642137_tn?1336198113
An elisa test is used to screen for hiv by detecting antibodies produced by the immune system as a defence against the virus,if positive a western blot is then performed to detect antibodies against specific antigens.It,s a more sensitive test.
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173692_tn?1334017348
Testing guidelines require two positive test results and confirmed by a positive confirmative test such as the Western Blot.
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Avatar_m_tn
So you guys are telling me that 2 negative Western Blot's mean absolutely nothing without the Elisa?

How come if someone has a positive Elisa and a negative Western Blot then it's negative? That obviously means Western Blot is stronger than the Elisa.

Sorry if I'm coming out annoying but my question still isn't answered.
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1519393_tn?1306805708
http://www.prepaidlab.com/HIV-STD-Tests/HIV-SCREEN-Western-Blot-Confirmation-on-Positives-
Did you read this?
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1519393_tn?1306805708
Also known as: HIV Antibody, Preliminary Test/Confirmation (HIV-1/O/2).  You took the wrong test! Preliminary means to proceed. Confirmation means to confirm!
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Avatar_m_tn
The Elisa test is not on prepaidlab. This is why I am asking **if Western Blot counts**, I am aware that it is usually taken after the Elisa. I am also aware that it is only to confirm.

What I am saying is do my 2 Western Blot NEGATIVE tests (after 6+ months) really mean negative even though I didn't get the Elisa? If I had HIV I don't think the Western Blot would tell me negative, right?
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Avatar_m_tn
yes, western blot counts. if 3 bands (parts of the hiv regions) show up in wb, then it's positive. else it's negative. elisa, ie oraquick, uses only 1 or 2 bands (for hiv-2) of synthetic antigen for antibody detection. it takes time for immune system to produce antibodies. pcr detects antigen directly (instead of antibodies) and must appear for antibodies to develop. if there's very little hiv, then very little antibodies are produced or there isn't enough time for antibodies to produce sufficient amounts, so elisa may be weak. 6+ months should be more than enough time for antibodies to show up (99.9+%)
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173692_tn?1334017348
Bye and have a good day.
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Avatar_m_tn
you too. =)
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