HL-3 saline

Reagent	Quantity (for 1 L)	Final concentration
NaCl	4.09 g	70 mM
KCl	0.37 g	5 mM
MgCl₂•6H₂O	4.07 g	20 mM
NaHCO₃	0.84 g	10 mM
Sucrose	39.4 g	115 mM
Trehalose	1.89 g	5 mM
HEPES	1.19 g	5 mM

Dissolve the reagents in H₂O. Bring the pH to 7.2 and adjust the final volume to 1 L with H₂O.
Add CaCl₂ from a 1 M stock solution to give the desired concentration of Ca²⁺ (normal saline has 2 mM Ca²⁺).^a

^aFor information on Ca²⁺ concentrations, see Stewart et al. 1994 (Stewart BA, Atwood HL, Renger JJ, Wang J, Wu C-F. 1994. Drosophila neuromuscular preparations in haemolymph-like physiological salines. J Comp Physiol (A) 175: 179-191); Broadie 2000 (Broadie KS. 2000. Electrophysiological approaches to the neuromusculature. In Drosophila protocols [ed. W Sullivan et al.], pp. 273-295. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY).