The National Institutes of Health intends to award a firm-fixed-price purchase order to Cytek Biosciences for preventive maintenance and repair services on a Cytek Aurora 5-Laser Flow Cytometer. Cytek is cited as the only responsible source due to its exclusive access to proprietary parts, software, diagnostic tools, and factory-trained engineers. This notice is not a request for competitive quotes, but interested small businesses may submit a capability statement demonstrating their ability to perform the requirement. An award is anticipated approximately five days after the notice unless another vendor demonstrates capability.