Hanks' salts explained

Hanks' salts is a collective group of salts rich in bicarbonate ions, formulated in 1940 by the microbiologist John H. Hanks.^[1] Typically, they are used as a buffer system in cell culture media and aid in maintaining the optimum physiological pH (roughly 7.0–7.4) for cellular growth. Due to their poorly reactive nature and small concentration in solution, Hanks' salts are mainly used in media that are exposed to atmospheric conditions as opposed to incubation. Performing the latter drastically exceeds the buffer capacity of Hanks' salts and may result in cell death.

The recipe according to AATBIO^[2]

Table 1. Required components

Component	Amount	Concentration
NaCl (mw: 58.44 g/mol)	8 g	0.14 M
KCl (mw: 74.55 g/mol)	400 mg	0.005 M
CaCl2 (mw: 110.98 g/mol)	140 mg	0.001 M
MgSO4-7H2O (mw: 246.47 g/mol)	100 mg	0.0004 M
MgCl2-6H2O (mw: 203.303 g/mol)	100 mg	0.0005 M
Na2HPO4-2H2O (mw: 177.99 g/mol)	60 mg	0.0003 M
KH2PO4 (mw: 136.086 g/mol)	60 mg	0.0004 M
D-Glucose (Dextrose) (mw: 180.156 g/mol)	1 g	0.006 M
NaHCO3 (mw: 84.01 g/mol)	350 mg	0.004 M

1. Prepare 800 mL of distilled water in a suitable container.
2. Add 8 g of NaCl to the solution.
3. Add 400 mg of KCl to the solution.
4. Add 140 mg of CaCl₂ to the solution.
5. Add 100 mg of MgSO₄-7H₂O to the solution.
6. Add 100 mg of MgCl₂-6H₂O to the solution.
7. Add 60 mg of Na₂HPO₄-2H₂O to the solution.
8. Add 60 mg of KH₂PO₄ to the solution.
9. Add 1 g of D-Glucose (Dextrose) to the solution.
10. Add 350 mg of NaHCO₃ to the solution.
11. Add distilled water until volume is 1 L.

References

1. Relation of oxygen and temperature in the preservation of tissues by refrigeration. 1 June 1949. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine. New York, N.Y.. 71. 2. 196–200. 18134009. Hanks JH, Wallace RE.
2. Web site: HBSS (Hank's Balanced Salt Solution) Preparation and Recipe AAT Bioquest. 2021-07-06. www.aatbio.com.