20.109(F15): TA's notes for module 3

Day 1

The week preceding the lab:

• Make LB:
  • 10 g tryptone
  • 5 g yeast extract
  • 10 g NaCl
  • 1 L deionized water
  • autoclave 30 minutes

On the instructors' bench:

• 50 mL conical tubes
• 25 mL pipets
• a couple of motorized pipet aids
• 2 mL eppendorf tubes
• TBS: 500 mL
• PEG/NaCl: 500 mL
• deionized water: 50 mL
• quartz cuvettes

On the students' bench:"

• bucket of ice
• 2 x 40 mL overnight culture of XL1-Blue infected with M13 phage
• 250 mL erlenmeyer flask

By the scale:

• (NH₄)₂Fe(SO₄)₂
• stirbars

In 4 °C fridge:

• orbital shaker (speed 120)

Day 2

Between Day 1 and Day 2:

• 1 M pH 7.5 Na:PO₄ solution:
  • 2.6% Monosodium phosphate, monohydrate - 2.6 g per 100 mL
  • 21.8% Disodium phosphate, heptahydrate - 21.8 g per 100 mL
  • These are calculated values that will result in a 100 mL solution of pH 7.5

• 12-16 hours after phage-Fe incubation, add

On the instructors' bench:

• 50 mL conical tubes
• 15 mL conical tubes
• tweezers (2 per team)
• TEM grids for practice (some)
• new TEM grids (2 per team)
• sign-up sheet for location of samples in TEM holder
• 100% ethanol (20 μL per team, so a couple of 1.5 mL eppendorf tubes suffice)

On students' benches:

• Na:PO₄
• M13 phage with(NH₄)₂Fe(SO₄)₂

quantities to be updated by George