Phase contrast visualization of squamous cell microridges.

A successful attempt has been made to identify microridges on squamous cells in routine smears using phase contrast microscopy. Microridges may be identified on mature cells of buccal mucosa and in cervical smears, either alcohol or spray fixed, and even in smears up to five years old. The features identified with phase contrast may also be observed with scanning electron microscopy. Identification of microridges may be of diagnostic interest in the evaluation of cervical smears.