They are using Hema-Strip,I heard from the net that it can detect antibodies even earily than standard elisa..not FDA approved but approved by singapore govt..FDA approved only matters when the product is used in USA..3 or 4th generation only matters in the first 6 weeks...after 6 weeks..every test is the same..4th generation test is actually a combo of P24 antigen and 3rd generation elisa...which is meaningless if u take the test at 12 weeks...the P24 antigen only exist in the blood at the first 21-28 days..