By precisely positioning and focusing a microscope on specific brain tissues, researchers can identify and analyze cells of interest, and detect changes in neurological diseases. One such microscope, the Stereo Investigator 7 from MBF Bioscience, Williston, Vt, (mbfbioscience.com) comes with high level motion-control that locates the errant cells. “Neuron tracing or stereology needs extreme precision in the x, y, and z axes,” says MBF Bioscience vice president Paul Angstman. “A key to the Stereo 7 system is the automated focal changes that allows detecting the cells. This is done with motorized stages that include a Metro linear gauge from Heidenhain Corp., Schaumburg, Ill, (heidenhain.com) that's accurate to ± 0.05 μm.

MBF engineers mount the Metro 1271 gauge on the microscope's z-axis. It works with the stage controller for precise movements and focus. A guided plunger lets the gauge tolerate high radial forces that might come from bumping the device.