Tasks for Oct. 21
- To prepare new dialysis of 30:1 colloid solution vs CaCl2 using MWCO 3500
- To prepare iodide ion selective electrodes
- To determine the molecular weight of the gel from electrophoresis started on Oct. 15
I- ISE preparation
Prodecure as describer by Dr. Fox on Oct. 21
- Prepare 10 mL 3 M NaCl
- Carefully remove yellow plastic covering on Ag/AgCl electrode (as instructed)
- Place electrode in 15 mL falcon tube with enough NaCl solution to match volume in electrode
- cover and store upright until needed
- Prepare 50 mL 4 M KNO3
- Add KNO3 to outer double junction cell, filling narrow tube + ~ 0.5 inches further
- Place electrode in small vial with enough KNO3 solution to cover the vycor tip
- Prepare 50 mL 0.01 M KI + 0.1 M KNO3
- Cut a short piece (~ 3 in) of silver wire
- Place in KI/KNO3 solution
- Electrolyze the solution using the power supply
- The standard reduction potential for Ag/AgI is -0.15 V
- Oxidation occurs at the anode, which is connected to the red lead
- Electrolyze at low power (low current) until the wire appears coated
- Test your electrodes with a range of KI solutions
- The Ag/AgCl electrode slides inside of the KNO3 bridge solution (this is a double junction electrode)
- The Ag/AgI wire can be connected directly to a multimeter using alligator clips
- You will continue to connect your Ag wire to the red lead on the multimeter
30:1 colloid solution vs CaCl2 (MWCO 3500) Dialysis Data
Ca2+ ISE
| CaCl2 concentration
|
mV measurement (mV)
|
| 5μM (1) |
|
| Colloid (1) |
|
| 50μM |
|
| Colloid (2) |
|
| 500μM |
|
| Colloid (3) |
|
| 5mM |
|
| Colloid (4) |
|
| 50mM |
|
| Colloid (5) |
|
|
Project name
