Neutral Buffered Formalin is a buffered non-coagulant fixative that rapidly penetrates tissues. First used to preserve tissue in 1893, formaldehyde-based solutions such as 10% and 20% buffered formalins are some of the most popular fixatives used in histology today. Buffered solutions are most often used because they have a considerably longer shelf life than unbuffered formaldehyde variants.
10% formalin is recommended as a general fixative for all tissues. The solution is stabilized with PBS at pH 6.8 and contains 4% formaldehyde with 10% methanol.