Services | Microbial Characterization Process
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Single, Isolated Colony
Samples must be 72 hours old or less. Any sample received that is more than 72 hours old will be subcultured upon arrival for fresh growth. Turnaround time for the sample will begin upon successful subculture. |
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Heat Treatment
Each sample is heated to inactivate the enzymes that degrade DNA. |
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Cell Lysis and Digestion
The cells are lysed to release the DNA and other cell contents. The DNA is then cut into fragments with restriction enzymes. Our standard characterization test involves cutting each sample with 2 separate enzymes (EcoRI and PvuII) in 2 separate digests. Analysis with 2 enzymes results in greater discriminatory power than analysis with a single enzyme. |
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Electrophoresis
The DNA fragments are separated by size using gel electrophoresis. The fragments are then transferred to a membrane. |
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DNA Probe Hybridization
The DNA probe for the ribosomal genes is hybridized to the fragments and a chemiluminescent agent is applied to cause the fragments to “light up” and show a band pattern. |
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Report Generation
A report is generated that displays the 2 banding patterns obtained for the sample after cutting the sample with the 2 restriction enzymes, EcoRI and PVUII. |
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Comparison
Upon request, submitted samples are compared to each other or to any previously submitted samples to examine the relatedness at the strain level. Comparison example: A contaminant was found in a final product that was the same species as contaminants found in a raw material and on the hands of a laboratory technician. Automated ribotyping was used to determine the source of the contaminant in the final product. From the fingerprint patterns seen here, it is clear that the strain found in the final product is similar to the strain found on personnel hands and different from the strain found in the raw material.
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