Appendix A Standard Operating Procedures - University of Rhode ...

Corrective Action
New and old plates must exhibit bacteria growth. If new plates do not exhibit bacteria growth,
but the old plates do, then the batch of new plates is assumed to be unable to support bacteria
and discarded. If both the new and old plates do not exhibit bacteria growth then it is assumed
that the plates were not inoculated properly and the inoculation procedure is repeated.
Notes regarding dilutions for QA samples
Volume of
sample
filtered
(mL)
Dilution tube preparation Volume
placed on
filter (mL)
Calculated Result
(# of colonies divided
by calculated result =
colonies/100 mL)
0.1 1 mL E. coli inoculated TSB sample
into 9 mL of PBS
1 1,000 or 10 -3
0.01 1 mL 10 3 sample into 9 mL of PBS 1 10,000 or 10 -4
0.001 1 mL 10 4 sample into 9 mL of PBS 1 100,000 or 10 -5
0.0001 1 mL 10 5 sample into 9 mL of PBS 1 1,000,000 or 10 -6
0.00001 1 mL 10 6 sample into 9 mL of PBS 1 10,000,000 or 10 -7
0.000001 1 mL 10 7 sample into 9 mL of PBS 1 100,000,000 or 10 -8
5.3 Analysis Method
5.3.1 Preparation – 1 Week Before Scheduled Sampling
1. Check to be sure the UV box works. If the lights flash and turn on when the black button
at the left end of the box is depressed – it works. Be sure not to stare at the light as it
can burn your retinas! If it doesn’t work contact Elizabeth Herron to have the box
repaired.
2. Check to be sure there is an adequate supply of mTEC media plates that are less than 1
month old. If there are not enough plates, more must be prepared. Preparation
instructions are found in Section 5.3.1.1.
Materials
5.3.1.1 Preparation of mTEC Media Plates
Envirocide or Conflict Magnetic stirring bar
Sterile Petri dishes Magnetic stirring and heating plate
Autoclave Metal tray
2 - 2 L autoclave safe flasks Aluminum foil
Insulated autoclave gloves Sterile 25 mL pipette
Dehydrated mTEC media Empty foil lined cardboard box
Deionized (DI) water Electronic pipette-aid
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Ambient Waters Microbiological Procedure SOP 007
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