Understanding Water Testing Methods – Colilert, MPN, and MF

Introduction Welcome to the PBR Laboratories newsletter! This edition explores three water testing techniques: Colilert, Most Probable Number (MPN), and Membrane Filtration (MF). We compare these methods to help you understand their processes, reliability, accuracy, applications, and limitations.

Colilert Method

Process: Colilert is a rapid test for detecting coliform bacteria and E. coli in water using a color-changing reagent. The sample is incubated for 24 hours. If coliforms or E. coli are present, the sample changes color.

Reliability: Highly reliable for detecting coliforms and E. coli due to specificity and sensitivity. Ideal for routine monitoring.

Accuracy: Provides qualitative results, indicating the presence or absence of coliform bacteria and E. coli. Rapid and clear results are valuable for water quality assessment.

Best Applications: Ideal for monitoring drinking water, recreational water, and well water. Rapid results allow for quick decisions.

Limitations:

Qualitative Only: No quantitative data.

Specificity: Primarily targets coliforms and E. coli.

Cost: More expensive per test compared to traditional methods.