[15p-413-1~8] Recent optical bio-sensing in a microscopic region

[15p-413-3] Apodized phase contrast microscopy and its biomedical applications

〇Tatsuro Otaki^1,2,3 (1.Nikon, 2.Tohoku Univ., 3.The Univ. of Tokyo)

Keywords:phase contrast microscopy, apodization, asbestos

Apodized phase-contrast microscopy was designed for reducing halo artifacts and for imaging fine structures, especially for cellular organelles without staining. The apodization in optics is a kind of spatial filters. Fine fibres of asbestos can cause lung diseases. We assumed that a 0.2 µm of diameter objects can be seen in a liquid immersion media. The newly designed apodized phase plate has a phase ring which has one quarter phase shift throughout most of the visible region with 2% transmittances. It has also two apodization areas with 8% transmittances. Sensitivities were confirmed by using a test slide. The microscope with a plan fluor 40x, 0.75-NA apodized phase-contrast objective revealed 0.25 µm in width line shaped phase objects with 2.2 nm phase shifts. Fine fibres of asbestos with sub-micrometres in diameter were detected. Additionally, we proposed a new test method for identification of asbestos by applying the apodized phase-contrast microscopy. The test method utilizes dispersion of light. It is based on a measurement of refractive indices of the samples. We propose that this method applies to phase specimens without staining for biomedical applications.