Disadvantages of the hanging drop technique include the possibility of overlooking a few motile cells among countless nonmotile cells, and the observation process can be time consuming. The hanging drop technique is a method used for examining living microorganisms.
There are other disadvantages of using the hanging drop method. It is not a safe method to use when one is dealing with extremely pathogenic organisms, as humans can easily get an infection. Setting up the apparatus needed for the hanging drop technique takes time, and the cavity slides used are expensive. The coverslips, which are one part of the apparatus, are quite fragile, and handling them can pose a challenge.
Another method used for observing tiny organisms is the wet mount technique. The difference between the two is that the wet mount technique dries out more quickly than the hanging drop method. Since the hanging drop method does not dry out as quickly, it allows for longer examination of the microorganism and a more reliable observation. A third method of testing for organism motility is the semisolid motility test.
The hanging drop technique is also used in the process of protein crystallization, which is the formation of a protein crystal.