Histology Frequently Asked Questions

Histology FAQ

Staining, Histochemistry and Histotechnology

(Frequently Asked Questions)

Dr. John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London, Canada

FAQ Home > Fixation, freezing etc

Lidocaine in perfusion fixation

Question.

Lidocaine can be added to the fixative during perfusion I would appreciate hearing the Lidocaine concentration again.

Answer.

This is the recipe for lidocaine I used for perfusion-fixing mormyrids (an electric fish):

Lidocaine (= lignocaine = xylocaine) for use in perfusion fixation (Used to relax blood vessels to permit more complete exchange & infiltration of fixative.):

Lidocaine 50 mg per mL, dissolved 95% EtOH (warm to dissolve). Add slowly to perfusion solution with stirring to make final lidocaine solution concentration wanted (e.g. 1mg/mL = 0.1%)

Note: Do not add the lidocaine directly to the perfusion solution, especially if the solution contains salts! The lidocaine will not go into solution.

Philip Oshel
(oshel[AT]shout.net
or poshel[AT]hotmail.com)