| Detection limit | - refers to sensitivity of method
- sensitivity: lowest number of target organisms that can be detected by the method |
| Enrichment | - technique involving use of a nutrient medium (usually broth) that allows growth of microorganisms to detectable levels
- qualitative test
- use non-selective or selective media |
| Non-selective enrichment | allows growth of all organisms (target organism and background microorgansims) |
| Selective enrichment | - allows growth of target organism to detectable levels while inhibiting growth of background microorgansims
- commonly used for pathogens (Tetrathionate broth for salmonella, listeria enrichment broth for listeria) |
| Specificity | - ability of a method to differentiate the target organism from background microflora in a sample
- a method with high specificity will commonly produce fewer false positive results |
| False positive | - a sample that tests positive by the microbiological analysis but tests negative based on cultural methods |
| False negative | - a sample that tests negative by the microbiological analysis but tests positive based on cultural methods |
