The National Cancer Institute intends to award a sole-source contract to Nikon Instrument Inc. for replacement of the 488nm laser unit on its spinning disk confocal microscope, citing Nikon as the only responsible source due to proprietary architecture and specialized installation requirements. System compatibility and risk of damage from third-party service are the primary justifications for limiting competition. Interested small businesses may submit a written capability statement to demonstrate their ability to perform the requirement, though the government is not obligated to compete the award. An award is anticipated approximately five days after the notice closes. No budget or performance location is specified in the notice.