Dubious coronavirus testing Coronavirus tests can be manipulated so that a lot of people test positive for the coronavirus or very few people test positive for the coronavirus. How is this done? It is done by manipulating the cycle threshold (Ct). Currently, tests are set at 40 cycles which is too oversensitive. At 30 cycles or below (a recent study showed there no viral growth from samples with a Ct above 24) hardly anybody would test positive for coronavirus. The more cycles that you have to run to detect the coronavirus the less the viral load (the amount of virus in the body).