Formalin 4% in Carbonate Buffer with Neutral pH is a histological fixative solution used to preserve cell and tissue structures in the preparation of tissue sections and cell preparations. Formalin is an aqueous solution of formaldehyde, an aldehyde that cross-links proteins and nucleic acids to ensure stable fixation of cell structures.
The neutral pH carbonate buffer in this formalin solution has two main functions: First, it maintains the pH of the solution in the neutral range (around 7.0), which is important to ensure optimal fixation and preservation of tissue morphology. Second, it prevents the formation of formalin precipitates, which can occur when formalin is used without a buffer.
The 4% formalin carbonate buffer solution with neutral pH is a widely used fixation solution in histology and pathology because it allows good preservation of cell structures and uniform staining. It is also compatible with a variety of staining techniques, such as hematoxylin-eosin staining, immunohistochemistry and in situ hybridization.