Formaline pure, also known as formalin or formaldehyde solution, is a concentrated liquid solution of formaldehyde (CH2O) in water. It is commonly used as a fixative and preservative in various laboratory and medical applications, particularly in histology, pathology, and anatomical dissection.

Formaline pure is commonly used for the preservation of tissue samples in pathology laboratories, where it is used to fix specimens obtained during surgeries, autopsies, or biopsies. It is also employed in research laboratories for various experimental techniques and assays that require tissue preservation, such as immunohistochemistry and in situ hybridization.