Optical microscopy enters a new phase: 3D measurement through tomographic bright field imaging
(Phys.org)—A widely-used tool for studying cellular structure – indeed, a technique in use throughout biology – phase contrast microscopy converts optical phase shifts to changes in brightness. At the same time, several issues in phase contrast microscopy – including reliance on custom instrumentation, the considerable costs of phase contrast condensers and objective lenses, complex analytics, and disruptive sample perturbations – have constrained its application to studying cellular refractive index and dry mass density. Recently, however, scientists at Oregon Health & Science University demonstrated tomographic bright field imaging (TBFI) – a new optical imaging technique that, using a standard optical microscope, allowed them to perform three-dimensional measurements of these features, along with volume and density, in red blood cells.