Lead plates

1) in 4L flask:

       9 g peptone
      15 g yeast extract
      0.6 g amonium sulfate
       60 g agar

2) Bring up to 2400 ml H₂O and autoclave 20 minutes

3) add 600 ml of 20% dextrose (filter sterilized)

4) After agar has cooled to 55^oC, addd 5.4 ml of lead nitrate (0.5 g/ml) to a final conc. of 0.9 mg/ml.