Anesthesia for fry?

Chi-Bin Chien chien at
Wed May 29 15:58:59 EST 1996

Yiing Lin asked:

>I was wondering if anyone has worked out any protocol for anesthetizing
>zfish fry and bringing them "back"?  I've been trying to take pictures of
>fry which are live-stained and need long (1-2 minute) exposures, but they
>move around much too much.

At the risk of repeating what's easily found in the zebrafish book: Mesab
(a.k.a. tricaine, MS-222, or 3-aminobenzoic acid ethyl ester) works fine as
an anesthetic, and is readily reversible if you don't overdose the fish. A
final concentration of 0.05 mg/ml (in embryo water or tank water) should be
fine for larvae; if they're still twitching go up to 0.1 mg/ml. It's
important to adjust the pH of your solution to about 7, as Mesab is an
acid. It may also help to increase the viscosity of the medium, for
instance by mounting the fish in 2-3% methylcellulose.

--Chi-Bin Chien

< MPI fuer Entwicklungsbiologie |      phone: 49-7071-601 335 >
< Spemannstrasse 35/Abt. I      |        fax: 49-7071-601 305 >
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