Presence/Absence Tests for Water Quality Monitoring
The Presence/Absence (P/A) test is a qualitative method used to detect coliforms and E. coli in treated waters. Unlike the Most Probable Number and Membrane Filtration tests, the P/A test provides a simple "yes" or "no" answer regarding the presence of these organisms, without indicating their quantity.(The maximum contaminant goal of zero total coliforms in drinking water eliminates the need to enumerate coliforms in samples). Additional screening of the sample for fecal coliforms, Pseudomonas, fecal streptococcus, and others can be done by selecting an appropriate confirmation method.
Why Choose the P/A Test?
Ease of Use: Minimal training required, reducing errors associated with more complex enumeration techniques.
Effective Screening: Ideal for ensuring zero coliform organisms in large sample numbers.
Quick Confirmation:Presence-Absence media containing MUG allows for E. coli confirmation through fluorescence with minimal equipment and efficient turnaround time.
Pathoscreen™ can be used as an alternative method to coliform testing to obtain a P/A test result. This medium was developed for quick detection of common pathogens in drinking water, surface water, or recreational water. It relies on the production of hydrogen sulfide as an indication of the presence of pathogenic bacteria, such as Salmonella, Proteus, Klebsiella, Citrobacter, Clostridium, and Edwardsiella, which are commonly associated with fecal contamination.
Compliance and Confidence
Whether validating treatment effectiveness or contamination risks, our prepared presence/absence media provides reliable performance to protect public health and ensure regulatory compliance.
