Jornal de Citologia e Histologia

New Method to Restore Fading Papanicolaou Specimen Using an Optical Clearing Agentx

Abstract

Kiyotada Washiya, Makoto Sakurai, Saki Furutate, Estuko Okusawa, Shigeharu Hatakeyama, Haruhiko Yoshioka and Jun Watanabe

Cytological specimens are used only once for staining, and cannot be reused after preservation in paraffin blocks. If a technique is developed allowing restaining of precious/rare specimens or those for education, which have been discolored due to long-term preservation, to restore their former states, it will be extremely useful for the reuse of specimens. We performed this study to determine whether discolored specimens can be restored to their former condition by applying an optical clearing agent. For restaining, 131 Papanicolaou (Pap) specimens prepared from 13 to more than 30 years ago were used. Using an optical clearing agent (SCALEVIEW-A2), Pap restaining, endurance tests of the optical clearing agent by repeated use, and immunostaining were performed. After treatment with the optical clearing agent for5-10 minutes, discolored cytological specimens could be stably restained just as the initial Pap specimens. As a result of the immunostaining of specimens treated using this method, both the nucleus (Ki-67) and cell membrane (MOC31) were positively stained. The optical clearing agent did not deteriorate when used repeatedly ten times. Discolored precious cytological specimens could be restored using a optical clearing agent. Specimens processed using this method could also be immunostained, and so this method is extremely useful