20.109(S12): TA notes for orientation
Back to lab tour here
Put two lab notebooks at each of the seven central benches.
Up front at teaching bench:
- Two sets each
- Cuvette box
- 50 mL conical with water
- 15 mL conical with XC (check w/Agi re: OD prep; she may do this part instead)
- Pipet temporary waste container
- Agi extra pipets, tips
TA runs this station. Cover:
- Utility of a dissecting microscope
- Turning on, adjusting light
- Reading magnification (dot at sides!)
- Each student should practice focusing!
- Low, then high mag
- Mess up focus before they start
- Use hemacytometer as sample
- Taking a picture: zoom, save, playback
- Utility of a fluorescence microscope (if time)
At the balance:
- Sorbitol in 50 mL conical tubes, ~ 2/3 full, 9 of them
- Check weigh boat and stir bar stocks, wash spatulas
All across from Yellow group bench:
- Signs posted: linked here
- 3 sets each
- small beaker (150-250 mL)
- small graduated cylinders (100 mL)
- 0.5 L media bottle filled with distilled water, 2 sets only
- 25 mL pipets, 1 per team plus 2 extra
- pipet bulbs, 2 only
- Solution A:0.2M NaH2PO4.H20, 27.6g/liter H2O
- Solution B: 0.2M NaH2PO4.7H20, 13.4g/liter H2O
Clean pH meter ahead of time (see below).
Calibrate pH meter that day, using freshly poured calibration solutions the first of the two days. Hit "calibrate," go into the first solution until the reading stabilizes, hit "calibrate" again, and after all three solutions have been measured in this way, hit "measure"to save.
Have one test sorbitol solution available inside a 50 mL conical tube (prepared according to station 3).
- How to clean pH meter
- push hard (but not too hard!) on electrode cap to release until fluid flows out of the bottom (Agi can show first time)
- run under warm tap water 15 sec
- soak in 0.1 M EDTA solution for at least 15 min (take from bottle and move to beaker with stir bar)
- rinse with distilled water
- add fresh electrode fill solution (not the same as storage solution!)
- add fresh storage solution (not the same as fill solution!) to the 15 mL conical that holds the electrode
Specs should be turned on at the beginning of lab. Make sure the DU 730 wavelength scan is set to read between 300 and 900 nm. Prepare one set of reference solutions (prepared according to station 1), including a blank, and leave them on top of the DU 640.
Wipe down the equipment and the sample card with a damp paper towel to rid dust.
Post cards with famous scientist names on the equipment indicated.
Be prepared to give hints about where to find the safety shower, fire blanket, and spill kits.
Be prepared to answer questions about this version of Excel. (Mostly instructor.)
Be prepared to answer questions about this version of basic lab math. (Mostly instructor.)