Voltage clamp · IPSC · High chloride
IPSC internal solution recipe
A 50 mL high-chloride CsCl internal solution starting recipe for whole-cell voltage-clamp recordings of inhibitory postsynaptic currents.
Calculate a different volumeDefault batch
50 mL starting recipe
| Compound | Final (mM) | MW (g/mol) | Source | Add |
|---|---|---|---|---|
| CsCl | 140.0 | 168.4 | Powder | 1178.8 mg |
| HEPES | 10.0 | 238.3 | 100.0 mM stock | 5000.0 µL |
| BAPTA | 1.0 | 1004.0 | Powder | 50.2 mg |
| CaCl₂ | 0.2 | 111.0 | 1000.0 mM stock | 10.0 µL |
| MgCl₂ | 5.0 | 203.3 | 1000.0 mM stock | 250.0 µL |
| Mg-ATP | 2.0 | 507.2 | Powder | 50.7 mg |
| Na-GTP | 0.3 | 523.2 | Powder | 7.8 mg |
| QX-314 | 10.0 | 343.3 | Powder | 171.7 mg |
Why this internal?
A high-chloride CsCl internal increases intracellular chloride and can increase the driving force for chloride-mediated inhibitory postsynaptic currents under common voltage-clamp conditions. QX-314 is included in this recipe to suppress voltage-gated sodium conductances from inside the recorded cell.
Current direction and amplitude still depend on external chloride, holding potential, liquid junction potential, series resistance, and temperature. Confirm that the chloride configuration matches the intended experiment.
How the amounts are calculated
Powder
mg = mM × mL × MW ÷ 1000
Stock solution
µL = desired mM × final mL × 1000 ÷ stock mM
Before preparing the solution
Treat this as a starting formulation. Verify the exact salt form, hydration state, molecular weight, and assay on each supplier label. Adjust pH experimentally, bring the mixture to final volume, and measure osmolality. The nominal concentration sum is not an osmolality prediction.