Today in the lab I was mounting muscle biopsies on microscope slides after immunostaining them. These are tiny muscle biopsies from the feet, which have been immunostained with fluorescent antibodies in order to label the neuromuscular junctions. This is where a neuron meets a muscle and "tells" it what to do (i.e., whether to contract or relax).
Timelapse: Mounting muscle biopsies onto microscope slides.
After immunostaining, the muscles are placed onto microscope slides so that they can be looked at using confocal microscopy, to figure out whether a genetic defect in the motor neurons affects the development of the neuromuscular junctions.
An example of what the samples look like under the microscope is shown in the image below.