MPN - Presumptive and Confirmed Test for Coliform
Use Lactose Broth (M74) or Lauryl Tryptose Broth (M76), at single strength in 10 ml volumes. For 5-tube MPN analysis, inoculate the 5 tubes at each dilution as follows:
To each of 5 tubes, add 2 mL of the blended homogenate (equivalent to 1 g of shellfish).
To each of 5 tubes, add 1 mL of 1:10 dilution of homogenate (0.1 g shellfish).
To each of 5 tubes, add 1 mL of 1:100 dilution of homogenate (0.01 g shellfish).
To each of 5 tubes, add 1 mL of 1:1000 dilution of homogenate (0.001 g shellfish).
Further dilutions may be necessary to avoid indeterminate results. Incubate tubes at 35°C ± 0.5°C then follow instructions in section 1.C and perform Confirmed test as in 1.D above, under "Conventional Method for Coliforms, fecal coliforms and E. coli". Calculate MPN as described in section 1.D above, except that shellfish analysis specifies that the coliform density be expressed as MPN per 100 g of sample rather than per g.
MPN - Presumptive and Confirmed Test for ColiformUse Lactose Broth (M74) or Lauryl Tryptose Broth (M76), at single strength in 10 ml volumes. For 5-tube MPN analysis, inoculate the 5 tubes at each dilution as follows:To each of 5 tubes, add 2 mL of the blended homogenate (equivalent to 1 g of shellfish).To each of 5 tubes, add 1 mL of 1:10 dilution of homogenate (0.1 g shellfish).To each of 5 tubes, add 1 mL of 1:100 dilution of homogenate (0.01 g shellfish).To each of 5 tubes, add 1 mL of 1:1000 dilution of homogenate (0.001 g shellfish).Further dilutions may be necessary to avoid indeterminate results. Incubate tubes at 35°C ± 0.5°C then follow instructions in section 1.C and perform Confirmed test as in 1.D above, under "Conventional Method for Coliforms, fecal coliforms and E. coli". Calculate MPN as described in section 1.D above, except that shellfish analysis specifies that the coliform density be expressed as MPN per 100 g of sample rather than per g.
การแปล กรุณารอสักครู่..
