GE OSMONICS MILLENIUMTM REVERSE OSMOSIS UNIT - Manual (Page 63)

M Millenium™ RO System by GE Osmonics
14693e - 31 Mar 03 4- 26 Routine Maintenance
4.5 Product Water Culture
FREQUENCY: Once a month or more often, depending upon culture results, and unit
protocol. We recommend before and after disinfection.
Materials Required:
• Bucket or similar container
• Sterile specimen container, such as Millipore (red) or 3M Commercial Standard
Plate count sampler, or a container your lab may require
RATIONALE: This procedure will help ensure that the microbial count of the product
(RO) water falls within the AAMI Hemodialysis Water Standard. The AAMI standard
maximum allowable concentration for bacteria in product water is 200 colony-forming
units. A bacterial count above the maximum level may be harmful to the hemodialysis
patient.
OTHER: Consult your lab to find out what type of sterile container to use and how
much product (RO) water is required to perform the test. Make certain that your
laboratory is informed of the correct procedure for performing a product water culture. A
"spread plate method" NOT a "calibrated loop" technique should be used, with tryptic
soy agar or equivalent agar, NOT blood or chocolate agar. If tested incorrectly, the
results may be inaccurate. The sample should be assayed within 30 minutes of obtaining
it, or refrigerated (5
° C) immediately and assayed within a 24 hour period. Obtain the
samples wearing long sleeves and a mask to prevent contamination of samples, use a
“mid-stream” “clean catch” type procedure.