Tests are carried out to detect two particular COVID-19 genes and, if a patient has both, the test registers as positive.
Sergio Perez is in self-isolation outside Silverstone after a routine COVID-19 test could not conclude whether the Mexican has tested positive or negative for the virus.
Unlike the positive involving a McLaren team member in Melbourne back in March, which forced F1 to abandon its opening race weekend entirely, the protocols now are far tighter and Perez's positive is unlikely to have a huge knock-on effect.
Racing Point said it was still planning to field two cars in Sunday's race, but a replacement for Perez was not immediately named.
Perez and some of his Racing Point team mates were self-isolating ahead of the race at Silverstone after the Mexican driver's initial test came back as inconclusive.
"Perez has entered self-quarantine in accordance with the instructions of the relevant public health authorities, and will continue to follow the procedure mandated by those authorities", read a statement issued by Formula 1 and the FIA.
"The procedures set out by the FIA and Formula One have provided for swift containment of an incident that will have no wider impact on this weekend's event".
Practice for the British Grand Prix, the fourth round of the Formula One season, starts on Friday.
The Silverstone-based outfit could turn to Mercedes reserve driver Esteban Gutierrez or Stoffel Vandoorne to replace Perez, although the latter's preparations for the Formula E season finale in Berlin complicate the situation.
Perez missed his scheduled Thursday news conference appearance because of the inconclusive test. Those individuals were quickly isolated and removed from operations ahead of the race weekend in Hungary, allowing the grand prix to continue as normal.