Week 13:
Exercise 23 (modified)--Identification and Quantitation of Microbial Numbers in a Water Sample
- Quiz 6
- Continue unknowns, if necessary.
- Explain background for water quality testing.
- Explain difference between coliforms and non coliforms and how to differentiate between E. coli and
E. aerogenes (IMVIC tests) and why it would be important.
- Why are we using EMB medium?
- Explain how to calculate concentration of bacteria in original water sample based on number of colonies in filtrate.
Lab Orders for Week 13
- Equipment:
- Membrane filter, 1 per group
- Vacuum apparatus (TA's will find this)
- Sterile graduated cylinders (not glass), 50 ml and/or 100 ml, as many as possible (minimum 2 per section)
- Forceps in alcohol in glass beakers, 1 per group
- 1 10 ml pipette per group
- Cultures for students (1/group):
- Simulated water sample
- Media:
- 1 small EMB plate per group
- 3 1 liter flasks of 500 ml sterile water for TA's on Sunday before lab (to make simulated water sample)