Louisiana Department of Health & Hospitals | Kathy Kliebert, Secretary

Statewide Initiatives

211 - Get Connected. Get Answers.

Coliform Enumeration of Dairy Samples

PHL Location

Amite Laboratory

CPT Code



Coliform Plate Count

Brief Description of Test

Used for the enumeration of coliform colonies of a given sample in pasteurized milk and dairy products.

Possible Results

Number of colonies per ml or gm

Reference Range

For all pasteurized milk and dairy products <1 per ml or gm ECC to 10 per ml or gm

Specimen Type

All pasteurized milk and dairy products.

Specimen Container(s):

Pasteurized milk and dairy products are collected in the container in which they are sold in the retail outlet.

Minimum volume accepted:

At least a half-pint (when collecting half-pints there are normally two samples collected to insure sufficient volume for testing.)

Collection Instructions

Collect a representative sample according to established protocol.

Storage and Transport Instructions

Samples must be stored on ice, the ice cannot cover the sample, and the sample must not be under water anytime during transport or upon receipt. The sample must be received so that the initial testing can be completed prior to 48 hours from the original collection time. Samples must be received into the lab with a pilot temperature sample that is at least half the size of the largest container size collected. The temperature of the pilot sample upon receipt must be between 0.0-4.4¢ªC (an exception to this is: the temperature of the pilot sample can be up to 7.0¢ªC as long as the original collection temperature was not >7.0¢ªC and the time of receipt is ¡Â 3 hours from time of collection).

Causes for Rejection

  1. Temperature of pilot sample does not meet requirements.
  2. Time of receipt >48 hours from collection.
  3. Sample container is unprotected or under ice or under water when received.
  4. Sample frozen or has ice crystals.
  5. Temperature control is missing.
  6. Sample leakage.
  7. Unsatisfactory container.
  8. Insufficient sample quantity.

Limitations of the Procedure

This procedure does not provide the source of a high coliform count.

Interfering Substances

The presence of any substance that interferes with bacteria count, i.e. disinfectants or antibiotics.


  1. Standard Methods for the Examination of  Dairy Products.
  2. FDA 2400 Series for the Examination of Dairy Products: Coliform Count
  3. US FDA/CFSAN Grade A Pasteurized Milk Ordinance.
  4. Laboratory Milk and Dairy Products SOP Manual.

Additional Information

A completed Lab 50 form must accompany the sample(s) with the date and time of collection, temperature at collection, name of the submitter, milk regional office from which sample was submitted, codes dates for the sample along with the codes for sample type and container type and size. Each ice chest must have its own pilot sample. If the sample is being submitted for specific testing this must be in the remarks section.