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?


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.


We are now Open on Weekends.

We have 5 locations conveniently located at Robertson Walk, Bencoolen Street, Novena, Scotts (Pacific Plaza) and Somerset (H&M)

Robertson Walk          6238 7810   map

Bencoolen Street        6884 4119   map

Novena                           6397 2095   map

Scotts                              6694 2348   map

Somerset                       6262 0762   map

Email: [email protected]

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. Hello, my test result is non reactive. I took my test 13 months after possible exposure. I think the test was 4th generation test. But here the website address and talk about seronegative and I see some people ask also. If someone happen to be seronegative (somehow just doesn’t produce antibody to HIV for some reason), does it mean that the 4th gen test is going to be positive even if the test is done 13 months after exposure? Because it detect the antigen? Is it too late to detect antigens then if the body is somehow not producing antibodies?

    • Your test is conclusive, you do not have to worry. If antibodies were not present in seronegative infection, antigen would be detected. You can move on.

  2. Hi dr.i went to testing center to take a test.51 days after exposure using alere test dont know what generation is.and result NR for both HIV and syphillis.is that conclusive if they only used 3rd generation test.

  3. Worried crazily

    Hi doc,

    I went to dentist for dental cleaning.
    On the 12th day after my visit, i got this gritty sensation in my mouth such as under the tongue, lower gums towards the back, inside cheeks. I noticed very very tiny white spots on the 6-7th day of this grittiness. This gritty feeling lasted for 7 days. I have never experienced this before in my life.

    I am afraid the nurse forgot to change the equipment since when the nurse told me to come in, she directly escorted the previous patient to somewhere else. Not long after the nurse came back and directly did my cleaning.

    I am super worried since i tried to search and many said it was thrush. And many said oral thrush related to Hiv.

    I have never done sex. No drugs as well.

    I got tested using hiv ag ab CMIA test on the 2nd week (14 days) and 5th week 3 days ( 38 days) after the dentist visit, all comes back negative.

    Is my test conclusive? What should i do next?

  4. Hi Doctor,

    I have protected sex with a commercial sex worker in August. I did a test at your clinic 15 days post exposure on 17 August 2017. I think it was the combo test. It was negative and the doctor on site said its 90% conclusive.

    Now, i am 48 days post exposure. If i take another combo test now, would it be 100% conclusive?


  5. Hello dr, using 4th gen duo test my results came back negative on the 15th day, 24th day, 29th day and 45th day. I’ve had a persistent cough the past week, are my results conclusive? should I stop taking the test? Thanks.

  6. Hi Doc I got an 4th generation laboratory test at 3 weeks post exposure (22 days) and then a Alere Determine 4th generation rapid test at 4 weeks post exposure (30 days). Both tests came out negative, are my results considered conclusive. I had protected receptive anal sex with a transgender by the way

  7. Hi Dr Jonathan
    I have tasted pcr quntative real time after 10 days of unprotected sex and the result was negative , after 21 i made compo test and it is negative . Is it counclusive ? Is there any need to retake test? Thank you i will pry to u

  8. I Had intercourse on 15th Aug 2017. Have done HIV DUO IV generation test on 16th Sep 2017 (app. on 30th days) . The result is Non Reactive (0.306). Am i infected with HIV? What does 0,306 means?

  9. Doctor, I have tested with 4th generation CMIA method for HIV at 1 year post exposure. Results is negative however I am concerned about seronegative infections. If I happen to be seronegative, can I say that my HIV test would have turned out positive as well because the antigens would have been detected?

  10. Hi Dr.

    I had a non reactive result with a 4th gen test 53 days after exposure (21 days after pep), would you say it is conclusive?

  11. Doc,

    I did finger prick testing yesterday and touched a door knob of the testing room while I’m still bleeding.

    Assuming there are stains of blood from previous person who took test is positive.

    Am I at risk? Because I believe the still bleeding finger prick is still considered fresh wound?

    My negative result was shortlived until I realised I touched the door with still bleeding finger prick.
    Shivering with fear now

    • No, you will not get HIV from a doorknob.

      • Hi Dr Jonathan,

        Thanks for the reply.

        I literally broke down today crying because of this.

        Is it a 100% assured that I won’t get HIV from a fresh finger prick wound from blood test with another person’s blood on door knob? Even if the stain on door knob is about 10mims old and it’s from someone HIV positive?

        I’m pretty sure my wound had direct contact on the knob from the test centre.

        I know my questions may be irritating but an answer could help me out abit. Also PEP necessary?

        • No, there is no risk at all and you do not need PEP.

          • Thanks for the clarification doc,

            Another crucial question,i had the following test below:

            1.Alere determine 4th generation test – 28 days, 43 days, 52 days – all negative (finger prick test)

            2. 30 days – 4th generation Elisa ab/ab blood drawn lab test – non-reactive

            Have you ever seen anyone turning positive after the 30 days ag/ab test (alere & Elisa)?

            Also is a test at 90 days (3months) recommended?

            Thanks for taking time to answer this doc.

          • No to both questions.

  12. Hi Dr,

    I am a male and I had performed multiple uprotected oral sex (cunnilingus) on a same woman of unaware status, and always condom protected vaginal sex (In a way like this; 2-3 acts per day for 4-5 days-first oral then vaginal). Do you think I am in a risk? Should i get tested?

    • There is extremely low to zero risk from oral sex. There is low risk from any penetrative vaginal sex, as condoms are not 100% protective.

  13. Last test

    Hi dr. Jonathan
    I was tested negative with 4th generation test at 17 days and now ı am tested negative with anti-hiv(chemiluminescence) at 45 days. İs it conclusive sir?

  14. Hi dr.after 28 days of unprotected sex i went to clinic to get tested.but they only used 3rd generation test.i know it is conclusive in 3months but what is the accuracy of this test in this period.thank you dr.

  15. Hi Dr I got a 4th generation hiv 1&2 antibody test 28 days after exposure the result was non ractive is my test conclusive? I’m in the United States and they suggested to test again in moths to ensure a conclusive result. Thanks

  16. Hi doctor
    I asked before about receiving unprotected oral and insertive protected anal with non broken condum i had couple more questions i am not sure if you saw them or not. I will copy them here

    You said “essentially Zero risk” does that mean i dont need to test?
    If i need to test, do i have to wait until the 28 days mark?

    I decided to take the RNA early detiction today at day 10 and will receive the results in 4 days!
    How accurate this test?
    If its negative do i still need to confirm it with 4th generation after 28 days?

    I am overly worried and anxious
    Thank you very much for your help.

  17. Hi Dr Jonathan,I have tested HSV and HIV Combo at days 58 .The result show I infect with HSV-1 but for HIV is negative so I would like to know is my HIV result conclusive or need to retest due to I infect with HSV-1.Hope u can reply me.

    • The HIV result is conclusive; no need for further testing.

    • Worried man

      Hello Doc, first of all i want to thank you for Help so many people with their worries and axiaety like me, second i have to apologize for my medium level english, here is my story, 4 months ago i had an indeterminate hiv result( 1 month after a protected sex with a sex worker), that scared me a lot and i went out of the lab to two more labs to confirm the result, in one lab the test come back negative and in the other come back indeterminate again, the bioanalist told me to no waste more time with 3rd gen and they ran a 4th gen test, it was negative thank god, but that was not enough to me to be completly calm, i repeat a 3rd gen a week after that ( negative), then 6 week after exposure( 3rd gennegative) 8 weeks (3rd gen negative) 12 weeks (3rd gen negative) and finally at 105 days 4th gen and hep C negative both.
      Are my 7 negative test ( including two 4th gen test) conclusive?
      Are a 4th generation test use a confirmatory test when a 3rd gen come back inderteminate or positive?
      Do i have to take another test at six month?
      Thanks for your comments

      • By definition you do not have HIV. Indeterminate tests can occur if there are cross-reactive antibodies such as from other retroviruses (a flu virus can cross-react even). I do not recommend further testing.

        • Worried man

          Thanks for your answer, if i were beggining seroconversion i should test positive in the following 5 test i had right?what are the odds of have a positive result after a 105 day negative 4th gen?
          About the symptoms i am expirience neck and joint pain, i had night sweats but no lymph nodes, no fever, no rash.

          In this country ( Venezuela ) we are lack of medicines and lab are lacks of reactives to run a wester blot, they are using 4th generation test to confirm a positive or inderterminate 3rd gen, is it a valid way to confirm the results?
          Thanks again and God bless you.

Leave a Comment

Thank you for your submission.

We will get back to confirm your appointment as soon as possible.

error: Content is protected
Copy Protected by Chetan's WP-Copyprotect.