(Source: M. Westerfield from Zebrafish Book 5th Edition)
Hank's solutions: Hank's solutions can be made from stock solutions (kept refrigerated, they will last for several months). A premix of the salts can be stored in the refrigerator for several weeks. Sodium bicarbonate does not store well, so it is made up fresh each time Hank's solution is made.
Full Strength Hank's: 0.137 M NaCl, 5.4 mM KCl, 0.25 mM Na2HPO4, 0.44 mM KH2PO4 , 1.3 mM CaCl2 , 1.0 mM MgSO4 , 4.2 mM NaHCO3
Hank's Stock Solutions:
Stock #1 8.0 g NaCl 0.4 g KCl in 100 ml ddH2O
Stock #2 0.358 g Na2HPO4 Anhydrous, 0.600 g KH2PO4 , in 100 ml ddH2O
Stock #4 0.72 g CaCl2 in 50 ml H2O
Stock #5 1.23 g MgSO4×7H2O in 50 ml ddH2O
Stock #6 0.35 g NaHCO3 10.0 ml ddH2O
Combine the following in order:
10.0 ml Solution #1, 1.0 ml Solution #2, 1.0 ml Solution #4, 86.0 ml ddH2O, 1.0 ml Solution #5
Store Hank's Premix in the refrigerator along with the Hank's solutions.
9.9 ml Hank's Premix, 0.1 ml fresh Stock #6