Why would it be better to look at living cells rather than dead cells?
It depends what you’re doing. If you’re going to be assessing function or seeing movement, you want to look at a live cell. For example if you wanted to see what happens when flagella grow, you need to have the cell alive to see that effect. If you’re studying anything with metabolism, growth, differentiation, you need to have the process happen to your sample under the microscope. The cell needs to be alive or these processes. If you’re going to look at a live cell you can’t stain it so you’re going to want to look at it in phase contrast. If you have any more questions or need clarification let me know.
