infocus #64 December 2021 UV transmission microscopy - optical imaging without glass

DOI: 10.22443/rms.inf.1.212

The aim of this work was to take an existing opticalmicroscope (an Olympus BHB) and convert it to be able to image in the UV, down to and potentially even below 300 nm, to enable the imaging of sunscreen ingredients in topical emulsions. Every aspect of the optical train was assessed and changed to enable UV to be transmitted and imaged. Where required optical transmission spectroscopy was used to understand the behaviour of existing and new components. After conversion it was able to successfully image in the UV at 313 nm and 365 nm and to discriminate between different types of sunscreens based on their optical properties. While presenting a number of technical challenges to the researcher, it has been possible to convert a standard optical microscope into one capable of performing UV transmission imaging. The ability to directly image sunscreen components based on their optical properties in the UV region demonstrates the usefulness of the technique and shows it still has a place in modern microscopy.