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How to Mount Zebrafish in Agar

Agar is also a plant abstract dissolved in fish water to ultimately make a gel that holds the embryo. The agar solution is added to the embryo when it is still a little bit hot and still semi-liquid. You must quickly position the embryo before the agar hardens to hold the embryo firmly so that it cannot move.  It is typically used with glass depression slides without a cover slip, and can be used for FIXED or LIVE embryos.

Chemical safety:  No hazards are listed for agar, and no protective gear is suggested, but you may want to wear gloves.  If it comes in contact with your skin or eyes, wash the affected area with soap and copious amounts of water and inform instructor.

1. Anesthetize the embryos/larva for mounting in Agar following the "How to use Anesthetics on zebrafish” protocol.

2. Make a 1.8% agarose solution in fish water solution.  The solid agar should be microwave until liquidize and the temperature of the solution should be warm enough that it can be touched, not overly hot.


3. Pipette one or two anesthetized embryos into a shallow glass depression slide.  Remove most of the water.


4. Add a small amount of agar; just enough to fill the depression of the slide.


5. Wait a few seconds to allowing the agarose to begin setting.

6. Move embryo into the preferred orientation using a loop. See “How to Make Embryo Loops”.


7. Allow agarose to completely harden, and then add a 1.5 mm cover slip to glass slide.