Background:  The serological screening tests are unable to detect the disease within their own defined window period making the recepients vulnerable to get infection. Aim:  To reduce the risk of TTI in recepients by repeating the tests with dissimilar results and increasing the grey zone range from 10 to 20 % below the cut of value.

Methods: Blood samples were screened for HIV–I and II, HBV and HCV byusing  chemiluminescencetechanique.

Results:   During January2016 to December 2016 a total of 27790 blood units were screened which showed 282 HBSAg(1.01%) positive ,222(0.79%) anti HCV positive and 53(0.19%)anti HIV  .Cumulative  percentage of all the blood units with OD(optical density) 0.90 and above was 2.0%.

Conclusions:  Doubtful negative results in Ag/ab screening for HCV, HBV and HIV should be retested. Any result showing OD 90 RLU and above should be discarded.