neutral buffered formalin 10% neutral buffered formalin (4% neutral buffered formaldehyde) A processed material that is a mixture of formalin (formaldehyde), phosphates, and water used as a standard fixative for diagnostic preparations. NCI BBRB Person: Chris Stoeckert, Helena Ellis, Jie Zheng buffered formalin http://stainsfile.info/StainsFile/prepare/fix/fixatives/formalin-buffered.htm processed material