Sunday, May 19, 2013

How Long Does a Conventional Culture Test Take?

A culture test is used to identify microorganisms from a specimen. A specimen can contain up to several microorganisms. After the specimen reaches the lab, a conventional culture test can be divided into two stages:
1. Separating each microorganism
2. Identifying each microorganism

In the first stage, the specimen is streaked on a nonspecific media where it will grow separated microorganism colonies. Colonies of the same species will have the same appearance, so the number of species in the specimen can be determined by how many types of appearance found. This process usually takes at least 18 hours, but ideally takes at least 36 hours.

In the second stage, each colony representing a species is Gram stained and tested with biochemical tests. A biochemical test will reveal one to several characteristics of the species. The more biochemical tests are done, the more characteristics are known. Each biochemical test takes at least 18 hours. A species usually requires several tests that are done simultaneously or gradually.

Identification of species is made by combining all information (the colony’s appearance, Gram type, and biochemical characteristics).

Conclusion: a conventional culture test will roughly take at least three days to complete.

Note: providing the laboratory with information about the specimen and clinical symptoms of the patient will help the test performance.

No comments:

Post a Comment