Modified Microbial Limits
The Modified Microbial Limits test is a qualitative test method for the detection of indicator organisms considered objectionable in human tissue samples. These organisms are Staphylococcus aureus, Streptococcus pyogenes, Enterococcus species, Clostridium species, Gram-negative bacteria, Enterobacteriaceae species and fungi (all mold and yeast). In addition, a standard plate count for total aerobic bacteria and molds and yeasts can be performed.
This test meets the requirement set by the AATB for environmental monitors, processing samples and finished products.
- USP 61/62
Standard turn around times (TAT) are listed below. Ask an expert for a specific consultation on your product. If you are ready to submit your samples for testing, click here to fill out the Sample Submission Form.
|Code||Test||TAT (days)||Request Quote|
|MEP110||USP 62: Suitability test, per organism||0||Add|
|MEP115||USP 61: Suitability test||0||Add|
|MEP250||USP 61: TAMC and TYMC||14||Add|
MEP110 - USP 62: Suitability test, per organism
TAT: 0 days
MEP115 - USP 61: Suitability test
TAT: 0 days
MEP250 - USP 61: TAMC and TYMC
TAT: 14 days
MEP110: The USP requires 10 grams/mL/patches/doses for the initial preparation, unless the batch is less than 1 L/kg. The Salmonella screen also requires 10 grams/mL of sample. It is recommended to supply 30-
MEP115: The USP requires 10 grams/mL/patches/doses for the initial preparation, unless the batch is less than 1 L/kg. It is recommended to supply 30-40 grams/mL/patches/doses for the USP <61> and <62> suitabi
MEP250: The USP requires 10 grams/mL/patches/doses for the initial preparation unless the batch is less than 1 L/kg. It is recommended to supply 20-30 grams/mL/patches/doses for the testing.
Study OutlineThe Modified Microbial Limits test procedure consists of enrichment for growth of minimal numbers of the test organisms, followed by plating onto selective and/or differential media. Specific verification of suitability of the tissue for the test must include a qualification study to demonstrate that the product is not inhibitory. This is accomplished by inoculating the product with the test organisms and demonstrating proper recovery.
Shipping: Samples should be submitted at a temperature similar to that in which the sample is stored. Extreme temperatures should be avoided. Water samples should be sent refrigerated (2 – 8˚C), and using expedited shipping.
Non-sterile plate count testing: USP <61> routine analysis is performed to determine the total aerobic microbial and total yeasts and molds counts. The plating of the sample can be performed by membrane filtration, pour plate or the spread plate method. The sample is diluted in an appropriate medium, generally Phosphate Buffer Solution, and then plated on Soybean Casein Digest Agar for total aerobic microbial count (TAMC) and Sabouraud Dextrose Agar for total yeasts and molds count (TYMC). Incubation is for 3 – 5 days at 30 – 35˚C for TAMC and 5 – 7 days at 20 – 25˚C for TYMC.