How do resistance genes compare to traditional sensitivities using cultures and stains?

The mechanisms to detect resistance using cultures and stains differ from PCR. While cultures and stains can test many antibiotics against an organism growing, PCR detects resistance genes harbored by the organisms. Cultures and stains are able to determine which organism is sensitive, intermediate or resistant to an antibiotic. This is in contrast to PCR which does not determine which organisms are expressing the gene, rather if the gene exists within the sample. In addition, PCR can only account for genes expressed and not other mechanisms of resistance that may make the antibiotic ineffective.