What are in vitro tests and their limitations and applications?what are the methods or test available for testing efficacy and safety of drug....

In vitro tests are done in test tubes or petri dishes; in vivo is the opposite, and literally means that it is done in a living organism.

The advantages of in vitro tests are that they can be done quickly and cheaply; tests can be done on different types of cells in vitro that could not ethically (or easily) be done on animals. A disadvantage is that because the test is NOT done on a complete organism, the results obtained may not apply in an intact plant or animal because of other systems functioning in the organism.