Modulators & Toxins

General Info

• Most modulators and toxins are kept in Drawers 37 & 38 (A, B, C, and D), the -20C freezer, or the fridge (next to the -20 freezer) in the main lab. 

  • • Please date any new container of modulator and be wary of bottles that are not labeled, but look a little old. (Consult Eve before disposing of these containers) 

• Read relevant literature to determine optimal starting concentrations.

• Use the balance by the Millipore water jug to measure small masses of the modulator.

  • • Please use the brush to clean off any spilled compound.

• Some temperature and light-sensitive stock solutions of toxins (PTX, TTX + sucrose, etc.) and neuromodulators are kept in the black locking fridge in the Dissection Room, under the sink. 

• If it's helpful here is a Molarity Calculator.

TTX

Most graduate students and post-docs know how to dissolve TTX powder. Do NOT make TTX solutions without the supervision/permission of these people or Eve.

• Making 10-7M TTX + sucrose for decentralization, etc.:

  • 1. In a 1ml Eppendorf tube, add and mix. You may also want to vortex it for a second or two, at the vortex on the Immunohistochemistry bench.

    2. 1ml (or 0.999ml) of 750mM sucrose.

    3. 1μl TTX 10-4M solution (usually prepared in a 10-4M solution in a 15ml tube wrapped with aluminum foil, and can be found in the locking toxins fridge).

PTX

• Most graduate students and post-docs know how to dissolve PTX powder. Do NOT make PTX solutions without the supervision/permission of these people or Eve.

  • 1. Add 60.3mg picrotoxin/100 ml Cancer saline into a 100 ml bottle. 

    2. Stir while moderately heating the solution to improve solubility.

    3. Parafilm the bottle while stirring.

• If you are making 10-5M PTX saline to isolate the pacemaker in your experiments: 

  • 1. Use the pre-made stock solution of 10-3M PTX in the black locking fridge and dilute by a factor of 100. 

    2. Then mix it to ensure the PTX gets homogenized.

       • Ex. To make 500 ml of saline with 10-5M PTX → add 5 ml 10-3M PTX to 495 ml saline and mix it a bit. 

Concentration Table

The amount of modulator to add to a given volume of saline can easily be calculated using this handy Excel file (slightly modified from Anne-Elise Tobin's version).