The IS-GCI series of microscope condensers from Siskiyou Corporation utilize Dodt gradient contrast (DGC) to provide a very simple means of imaging transparent, colorless objects, such as glass “patch clamp” probes, without the complexity and limitations of techniques based on phase and/or polarization. Specifically, IS-GCI condensers provide an off-axis illumination pattern that naturally creates contrast in a conventional microscope at sample edges, outlines and other sharp discontinuities with no other optics or special alignment required. They are available with or without an integrated LED light source option, including warm white (WW), dental blue (460 nm), green (525 nm), amber (590 nm), near-infrared (735 nm), or infrared (850 nm). These new condensers are compatible with the company’s open microscope platform, as well as tube-based microscopes from leading manufacturers including Olympus, Nikon, and Zeiss.
Imaging transparent, unstained samples has always been a challenge in microscopy. A typical example is the small glass micropipette electrodes used in electrophysiology. Other examples include organelles and other cellular components. The common method of DIC (differential image contrast) microscopy, such as Nomarski, involves optical complexity that can cause limitations when the contrast image is combined with some other measurement modality or imaging technique. The Dodt gradient contrast (DGC) method is an alternative approach proven to avoid these drawbacks, and these IS-GCI condensers bring simple plug and play functionality to this technique making it accessible to the widest possible audience.