mayo 2026

In deep tissue imaging using a confocal microscope, properly matching the refractive index of the immersion media (water or oil) in the objective with that of the specimen (cells or tissue) is key to acquiring high-quality 3D images. For example, when acquiring images of cells with a low refractive index (n≈1.35-1.38) using an oil immersion objective (immersion media: n≈1.52), both “Z-axis shifting (geometric shift)” and “image blurring due to spherical aberration” occur simultaneously, reducing the reliability of the data. This application note explains how these two phenomena affect 3D images.

Keywords: 3D imaging, Deep imaging, super-resolution confocal laser microscopy, refractive index mismatch, spherical aberration, Z-axis shift, point spread function (PSF)