A horizontal intravital microscope-plus-bone chamber system for observing bone microcirculation.

A horizontal intravital microscope has been built which utilizes the telescope optics format with infinity-corrected objectives. The intravital stage accomodates a rabbit into which a tibial bone chamber has been implanted. The chamber is itself an optical component and is considered an integral part of the system. Each animal is observed in supine position with its implanted leg held in an adjustable spring-loaded yoke which aligns the bone chamber in the optical axis. Long working-distance objectives and condensers allow for viewing of the slit-gap tissue in the bone chamber with both transmitted and epi-illumination; the latter being applied for fluorescence studies. A unique feature of the system is a transfer lens holder which can be relocated within the microscope tube. This adjustable lens holder allows for changing of transfer lenses, thereby freeing the investigator to utilize objective lenses with preferred numerical apertures for a given image size.