In Reply Refer To:
Mail Stop 412

September 24, 2007

Office of Water Quality Technical Memorandum 2007.06
Subject: Field Methods
-- Guidance for commercial sources for prepared microbiological media; original distributor no longer carrying recommended media

Purpose of this memorandum
This memorandum announces that Microbiology International, original recommended supplier of prepared microbiological media, no longer carries the U. S. Geological Survey (USGS) recommended media. Currently, this company is advocating the use of another media type. This new media type (nutrient pads) has not been tested by the USGS and is not recommended for USGS microbiological monitoring. Ohio Water Microbiology Laboratory (OWML) personnel have investigated other sources of recommended media and have suggested appropriate sources for use by the USGS. Contact information for commercial suppliers is provided. Appendix A includes information for purchasing recommended media from two suppliers and their contact information.

Note: When ordering pre-poured plates, note the size of the plates being ordered. Plates that are 60 mm in size do not fit in the older, blue Millipore heater block incubators. Plates that are 50 mm in size do fit these incubators. All of the plates fit in the newer Millipore single- or dual-chamber incubators.

Also, when ordering any pre-poured plates, note that there is a two to three week lead time required to ensure receipt of fresh plates. If plates are in stock, ask the supplier to locate information regarding expiration date of plates that will be shipped. Check to be sure the plates will not expire before use.

Please contact the OWML if requests cannot be met in a timely manner.

Timothy L. Miller /s/
Chief, Office of Water Quality

This memo supersedes Office of Water Quality Technical Memorandum 2005.02.

Distribution: All WRD Employees