Googled (try it next time [http://www.google.com/advanced_search?hl=en]) : http://members.aol.com/RSRICHMOND/histology.html

Davidson's fixative

PRINCIPLE: Davidson's (sometimes called Hartmann's) fixative is a rapid fixative which gives good nuclear detail with minimal formalin pigment. Specimens cut and stain as if fixed in ordinary formalin. Davidson's fixative contains no mercury or other metals.

SPECIMEN: Davidson's fixative is particularly useful for preparing tumors, bone marrow specimens, gynecologic material, fatty breast, and medical biopsies. It may be used for testicular biopsies and for overnight fixation of fat containing lymph nodes. Fixation of small specimens is rapid. Exposure to the fixative should be limited to 24 hours (tissue may be transferred to neutral buffered formalin or 70% alcohol for storage).

PROCEDURE: Mix

strong formalin (37%): 2 parts or 500 mL

alcohol: 3 parts or 750 mL

glacial acetic acid: 1 part or 250 mL

tap water: 3 parts or 750 mL

eosin: enough to color

REAGENTS AND SUPPLIES: Any source of these chemicals should be satisfactory. Proportions are not very critical. Reagent alcohol, or waste alcohol from staining, may be used.

QUALITY CONTROL: Davidson's fixative is clear and has no color other than that imparted by eosin. Color should be sufficient to render identification easy. The odor changes with age as esterification produces a characteristic "airplane dope" odor of ethyl acetate. Tissues placed in Davidson's fixative rapidly turn white and opaque, while blood turns brown.

SAFETY AND ENVIRONMENTAL: Acetic acid is quite corrosive. Davidson's fixative may be stored at room temperature in plastic or glass containers for an indefinite time.

REFERENCES: Davidson's fixative is not mentioned in most standard reference works on histology. It is named after William McKay Davidson, a British hematologist, and was publicized by Moore and Barr in their well-known studies of sex chromatin. Davidson's fixative is often called Hartmann's fixative because of its introduction by Dr. William H. Hartmann (later at Vanderbilt) while he was at Johns Hopkins.

Moore KL, Graham MA, and Barr ML. "The detection of chromosomal sex in hermaphrodites from a skin biopsy." Surgery, Gynecology and Obstetrics 1953;96:641-648.

Moore KL and Barr ML. "Nuclear morphology, according to sex, in human tissues." Acta Anatomica 1954;21:197-208.

Procedure written by Robert S. Richmond, M.D., F.C.A.P., July 1997.