Fly Saline
| Reagent | Concentration |
|---|---|
| NaCl | 103 mm |
| KCl | 3 mm |
| CaCl2 | 1.5 mm |
| MgCl2 | 4 mm |
| Glucose | 10 mm |
| NaH2PO4 | 1 mm |
| NaHCO3 | 26 mm |
| Trehalose | 10 mm |
| TES (N-tris[hydroxymethyl]methyl-2-aminoethane sulfonic acid) | 5 mm |
| Sucrose | ∼9 mm |
In advance of the experiment, prepare fly saline as follows, and store it for up to a half a year at 4°C.
-
1. Combine the reagents above. Adjust the osmolarity of the solution to 270–275 mOsm by changing the concentration of sucrose, which is not metabolized by the brain and acts as an inert solute.
-
2. Oxygenate the saline by bubbling a mixture of 95% O2/5% CO2 continuously through the solution for 20 min.
-
The pH should equilibrate to 7.3.
-
-
3. Bubble 95% O2/5% CO2 through fly saline for 20 min every time before adding it to the fly tissue to ensure that oxygen is saturated in the solution.
