Calcium Chloride Stock Solution Preparation and Recipe

To prepare L  Calcium Chloride Stock Solution

Table 1. Recipe

1. Prepare 0.8 L of distilled water in a suitable container.
2. Add 58 g of Calcium Chloride to the solution.
3. Add distilled water until the volume is 1 L.
4. Measure the osmolarity using an osmometer: if below 1000 mmol/kg, add more CaCl2; if above 1000, add H2O. (The osmolarity of 1000 mmol/kg is ~0.383 M. Preparation of this calibrated solution is necessary because calcium chloride is hygroscopic, so is not reliably measured by weight. Slight errors in calcium concentration have an outsized effect on synaptic physiology.) Store the solution at 4°C. Solution stored under these conditions appears to be stable for several months.