What are the advantages and disadvantages of the hanging drop technique and the motility medium technique?
The hanging drop technique allows you to examine a sample immediately. That could be a big advantage over a stab into a motility medium where you must wait for the organism to grow. Also, some microbes don’t grow in motility medium or require special incubation techniques to get growth. Beginners often have some difficulty seeing the growth if the microbes did not grow well in the medium. Also, the hanging drop has the drop of liquid suspended below a coverslip, it tends to be free to move more easily. Personally, I think the hanging drop is largely a waste of time and costs more because it requires a special glass slide. A simple wet mount placed on a routine glass slide and coverslip works just fine and is much more rapid. Most laboratories use the motility stab because they can set up a series of tests in a matter of minutes, incubate them and read them all at the same time the next day. It is rarely necessary to verify motility without having all the other tests at the same time, s
