Embryo Embedding Agarose

Recipe

Low-melt agarose stock^a (1%)	400 μL
HEPES (0.1 m, pH 7.3)	50 μL
MS-222^b (tricaine methane sulfonate; 0.4% stock in dH₂O)	50 μL

Melt 1% low-melt agarose in a microwave or water bath. Add HEPES and MS-222 to final concentrations of 10 mm and 0.04%, respectively. Keep on a heat block at 37°C until ready to use. Make fresh on the day of use.
^aPrepare 1% low-melting-point agarose (Invitrogen) in embryo medium (E3M). Store it at 4°C to avoid contamination.
^bStore the stock at −20°C as 1-mL aliquots.