Dr. Tan and Partners is one of the few approved Anonymous HIV Testing Centres in Singapore. A detailed write up on our service is available here.

Other STD services: Early STD Screening, Rapid Hepatitis B Blood Test, Swab for Gonorrhea and many more... contact us to make an appointment now!

HIV 4th Generation Test Singapore

The HIV 4th Generation Test is one of the most accurate and fastest way to determine is a person has been infected with HIV or not.

The HIV 4th Generation Test is also called the Combo test or the Duo test.

It tests for both the HIV antibodies as well as the antigens in the blood. It can be done as a rapid test i.e. you can get the results in 20 minutes.

Antibodies are produced by the body when it is infected with the HIV virus. There are many different types of antibodies. The one that is produced the earliest is called the IgM antibody. This can be produced as early as 20 days post exposure. 3rd and 4th Generation HIV tests can detect the IgM antibody.

Antigens are bits of the HIV virus shell that can be found in the blood as early as 14 days post exposure. The 4th Generation test can detect the presence of this antigen.

If the test detects either the presence of HIV antibodies or antigens, it means the patient is most likely infected with HIV. This has to be confirmed with another ELISA test. We always do at least 2 tests before diagnosing a person as HIV +ve.

Officially it is conclusive at 28 days post exposure. However, from current scientific data, we know that when the test is done at 20 days post exposure, it is already as good as 100% accurate. Personally I have tested patients +ve for HIV at only 14 days post exposure with this test.

The US CDC recommends the HIV 4th Generation test for all HIV screening. This is because it is more accurate, has a shorter window period and can pick up rare cases of sero-negative infections (see below).

The HIV 4th Generation test can detect HIV infections in very rare cases of people who are infected with HIV but never produce any anti-bodies. These are called sero-negative infections and happen in about 1 in 1 million people.

At our clinics the HIV 4th Generation test costs $150 (before GST).

You can walk in our clinics at Robertson Walk, Bencoolen Street, Novena Medical Center or Scotts Road anytime during our opening hours for this test. It only requires a finger-prick of blood and 20 minutes to get results.


We are Open on Saturdays and Sundays.

Click Here for Contact Details, Address and Opening Times.

Feel free to email your queries, feedback and suggestions on what other topics you want to see in the comments section below.


Click here for HIV Testing FAQ

More on HIV symptoms.

If you have any questions, visit our free online forum on sexual health, HIV and STDs.

Click here for Info on STD Symptoms in Men
Click here for Info on STD Symptoms in Women
Click here to see the full range of our HIV/STD Services

If you need a HIV test visit Our Clinics anytime during our opening hours. You do not need an appointment.


Find out more about Anonymous HIV testing at our clinics.

Can’t wait for 3 months to find out? Find out more about Anonymous Rapid HIV Combo test at our clinics.

If you had a high risk exposure to HIV within the past 72 hours, you can take medicines to reduce your risk of actually contracting HIV. Find out more on HIV PEP Treatment.


Related Topics:

Anonymous HIV testing at our Clinics

HIV – Understanding the Window Period

Cost of HIV/STD tests at our Clinics

Condom Broke

Getting HIV from Oral Sex

More on HIV symptoms

How long can HIV live outside the body?




Need more advice?

Come down to Our Clinics for a discussion with Our Doctors, or call our clinics for more information:

1.) Robertson Walk (Anonymous HIV Clinic)  (+65 6238 7810)

2.) Bencoolen Street (+65 6884 4119)

3.) Novena Medical Centre (+65 6397 2095)

4.) Scotts Medical Centre (+65 6694 2348)

5.) Somerset – Orchard Building (+65 6262 0762)



Where to find us – here

Selected clinics are open on Saturday and Sunday.

Email: hello@dtapclinic.com

All Our Doctors are Fully Certified and Trained to conduct specialised STD Screening,  STD Testing & STD Treatment and HIV Testing.

For lady patients who prefer female doctors, we have professional certified female Doctors to attend to your medical needs.

About Dr. Tan
Dr. Tan graduated from the National University of Singapore in 2001. His residency was in the two largest public hospitals in Singapore; Tan Tock Seng Hospital and Singapore General Hospital.

Find the profiles of our panel of doctors.


  1. Hi Doctor. I had protected vaginal sex with a girl but my worry is that after that, as i couldn’t complete, she removed the condom and gave me a handjob with the same hand.

    I have done the 4th gen Alere combo test 25 and 33 days post exposure, both negative.

    What do you make of my results based on my exposure risk?

  2. Jose Villalpando

    Hello, does a 4th generation test done one day after finishing PEP reliable? From your experience does a negative test right after finishin PEP turned positve later on ?thank you

  3. Hello i did hiv- ag- ab test 42 days aftter expuree and result ots negativ do i need to repeat test latter or not

    • I would consider this testing conclusive already.

    • Jose Villalpando

      Hello, a 4th generation test donde one day after finishing PEP reliable? From your experience does a negative test right after finishin PEP turned positve later on ?thank you

  4. Allan Anonymous

    Hi Dr,

    I (Male) had protected oral and protected vaginal sex with a female commercial-sex-worker in Vietnam.
    I had the following test done at respective days after the exposure:

    (1) HIV 1 Viral Load (PCR) Test (Cobas Taqman HIV 1) Version 2.0 at 3 days after exposure – Result: HIV1 RNA not detected

    (2) Immuno Assay RNA Viral Load RT – PCR (Taqman Real Time PCR) at 6 days after exposure – Results: HIV1-RNA not detected

    (3) HIV-RNA Viral Load (Taqman Real Time – PCR) at 6 days after exposure – Results: Target not detected

    (4) Immuno Assay RNA Viral Load RT – PCR (Taqman Real Time PCR) at 13 days after exposure – Results: HIV1-RNA not detected

    (5) HIV Ag/Ab (Screening) (CMIA) at 27 days after exposure – Results: Non-reactive (not detected)

    (1) ALL 5 tests resulted NEGATIVE, can I now consider this as a conclusive result that I am indeed HIV Negative without having to do any further tests (considering the above 5 tests with 4 of them being PCR tests, supposedly very accurate)?
    (2) Does it matter that I took the last (5th) test on day 27 and not on 28th as recommended for Ag/Ab test?

  5. Justine

    Hello Dr is the 4th generation rapid test conclusive any time after 28 days? lets say at 35 45 or more or it has to be taken exactly at day 28 after exposure to be accurate. Thanks in advance for your reply.

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