As soon as is practical after excision fix tissue specimens in glutaraldehyde fixative. SA Patholgy's standard fixative is 2.5% glutaraldehyde in 0.1M sodium cacodylate buffer. Other buffering agents such as phosphate are also acceptable.
The specimen can be collected into formalin and transferred to glutaraldehyde in the laboratory. If glutaraldehyde is unavailable the tissue can be fixed with buffered formalin, but the tissue morphology and diagnosis may be compromised.