It may help to discuss with your doctor the advantages and disadvantages of each test. For instance, results from a rapid strep test are available within 10 to 15 minutes, and results from a throat culture may take 1 to 2 days. A throat culture is more accurate. 1  A negative rapid strep test result can mean there are no strep bacteria present. 2  If the rapid strep test result is positive, a throat culture isn't needed.