Using the Mesolens for optical mesoscopic imaging of large specimens with sub-cellular resolution throughout
Gail McConnell (University of Strathclyde) is giving a lecture as part of the Advanced Imaging Forum.
For more than a century, the design of low-magnification microscope objectives has been guided by the angular acuity of the human eye. At x4 magnification, this requires a numerical aperture no greater than 0.1 or 0.2, which can be achieved cheaply and easily by simple optical designs. With the advent of confocal and multiphoton microscopy, however, it became apparent that the poor axial resolution of more than 30 microns with low magnification objectives was intolerable for these 3D methods.
We have developed a new and complex objective with a magnification of 4x and an NA=0.5 which we call the Mesolens. We specified this lens for mammalian embryology, and have shown that it can image every cell of a 6mm-long embryo 3mm thick with sub-cellular resolution if the tissue is cleared appropriately. The pupil size of the lens is so great that it cannot be used with a conventional microscope frame, so we have built the imaging system around the lens, and use either wide-field camera or point-scanning fluorescence detection to create images. We have applied the Mesolens to a range of biomedical specimens: I will present data from current applications and describe our plans to further develop the lens.