Cover photograph (Copyright © 2016, American Society for Microbiology. All Rights Reserved.): Rabbit peripheral blood leukocytes were mixed with 800 μM sodium urate in borate buffer and allowed to incubate at 37°C for 24 h in 5% CO₂, permitting uric acid crystals to form. The contents of the well were transferred gently to a cytological centrifuge and centrifuged at 28 × g for 5 min, and then the leukocytes were stained with the three-step stain. The slide was viewed under polarized light, with the polarizing filter rotated to reveal the birefringence of the uric acid crystals while still admitting enough light to see the rabbit leukocytes. (Photo courtesy of Agnieszka Lis, University at Buffalo, Buffalo, NY.) (See related article on page 976.)