Paraffin microtome and cryostat microtome are both types of microtomes used for sectioning biological tissue. However， they differ in their operating principles and features.

Paraffin microtome:

1. Operating principle: The paraffin microtome uses a blade to cut tissue into thin slices. The tissue is first embedded in paraffin wax， which is then heated to soften the wax and make it malleable. The blade is then used to cut the tissue into thin slices， which are then mounted on a glass slide for further analysis.

2. Features: The paraffin microtome is generally slower than cryostat microtome， but it is more versatile and can be used to cut a wide range of tissues. It is also less expensive than cryostat microtome.

Cryostat microtome:

1. Operating principle: The cryostat microtome uses a freezing stage to cool the tissue rapidly， while a blade is used to cut it into thin slices. The tissue is first embedded in a resin， which is then frozen and sectioned using a cryostat.

2. Features: The cryostat microtome is generally faster than paraffin microtome， but it is more expensive and requires specialized equipment. It is also more precise and can be used to cut very thin slices of tissue， which are ideal for electron microscopy.