Microsoft Word - 3M Petrifilm REC Plate OMA Manuscript 09121

ERP Methods Book

74

not use diluents containing citrate, bisulfate or thiosulfate with the 3M Petrifilm Rapid E.  1

coli /Coliform Count Plate; they can inhibit growth. Perform 3M Petrifilm Rapid E. coli /Coliform  2

Count Plate testing in a properly equipped laboratory under the control of a skilled  3

microbiologist. The user must train its personnel in current proper testing techniques: for  4

5

example, Good Laboratory Practices. 

6

7

Sample Preparation 

8

( a ) Use appropriate sterile diluents (BPBD or PSS). Do not use diluents containing citrate,  9 bisulfate or thiosulfate with the 3M Petrifilm Rapid E. coli /Coliform Count Plates, as they can  10 inhibit growth.  11 ( b ) For food samples, prepare test portion (10, 11 or 50 g) or equivalent ratio of sample to  12 diluent to create a 1:10 dilution as appropriate to the sample being tested. 13 ( c ) For environmental surfaces samples, add 25 mL of the appropriate diluent to each  14 sponge sample.  15 ( d ) Blend or homogenize sample as appropriate.  16 ( e ) For optimal growth and recovery of microorganisms in acidic products (< pH 5), adjust  17 the pH of the sample suspension to greater than pH 5. For acidic products, adjust with pH 1N  18

19

NaOH. 

20

21

3M Petrifilm Rapid E. coli/Coliform Count Plate Assay  

22

8

December 6, 2018