Hanks' balanced salts, aptly named after the microbiologist John Hanks who formulated the mixture, are a collective group of salts rich in bicarbonate (e.g. NaCl, KCl, CaCL2, etc.). Hanks' balanced salt solution (HBSS) is often used as a buffering agent in cell culture media and aids in maintaining the optimum physiological pH for cell growth, generally between 7.0 - 7.4.

As a buffer, HBSS also provides cells with water and essential inorganic ions to help cells maintain an appropriate osmotic balance within their microenvironment. Common supplemental compounds that are/can be added to HBSS in preparation to aid in cell culture efforts are listed below:

In research, HBSS has proven to be an effective medium for preserving viability, mitogenicity, and proliferation ability for an array of cell types. It has also been used in cell washing steps before dissociation, transporting cells, or diluting cells for counting. HBSS is commercially available, though many protocols are also available online.

AAT Bioquest's interactive HBSS recipe is available here, along with similar physiological buffers and others.