Pseudalert

The Pseudalert Test is designed for water samples including bottled, pool, and spa water. Bottled water samples are defined as samples taken from any point in the manufacturing of bottled water (from the original water to the finished product). Extensive studies were done on Pseudomonas aeruginosa stressed by the various chemicals and cleaning agents used in pools and spas to mimic the impact of treatment. The Pseudalert Test was specifically formulated and tested to ensure it would detect stressed P. aeruginosa in these samples.

The Pseudalert Test is based on a bacterial enzyme detection method that signals the presence of Pseudomonas aeruginosa through the hydrolysis of an enzyme substrate. P. aeruginosa cells rapidly grow and reproduce using the rich supply of amino acids, vitamins, and other nutrients present in the Pseudalert reagent. Actively growing strains of P. aeruginosa have an enzyme that cleaves the substrate in the reagent to produce blue fluorescence under ultraviolet light. The Pseudalert Test detects P. aeruginosa at 1 cfu per 100 mL or 250 mL sample within 24 hours.

Pseudomonas aeruginosa is the only Pseudomonas species known to cause health issues. For this reason, regulations in many countries apply specifically to P. aeruginosa detection.

The Pseudalert Test detects Pseudomonas aeruginosa at 1 cfu/100 mL or 1 cfu/250 mL.

There is no comparator for the Pseudalert Test. For comparison, use a negative control when interpreting results.

Water samples are incubated at 38°C ^± 0.5°C for 24 hours, and results are valid up to 28 hours.

No. Breakthrough of nontarget organisms can occur at temperatures other than 38°C ^± 0.5°C.

Yes, if the results are positive. An inoculated Pseudalert presence/absence sample that is positive for Pseudomonas aeruginosa before 24 hours is a confirmed positive test for P. aeruginosa. However, for an accurate quantitative determination of P. aeruginosa in a sample, the results should be read at 24–28 hours of incubation.

Yes, if the results are negative. If an inoculated Pseudalert Test sample is inadvertently incubated for over 28 hours, lack of blue fluorescence is a valid negative test result. However, blue fluorescence that develops after 28 hours is not a valid positive test result; the test should be repeated or verified.

Yes, both the Quanti-Tray and Quanti-Tray/2000 can be used with the Pseudalert Test in the 100 mL format but not the 250 mL format.

For presence/absence testing, use a sterile, transparent, nonfluorescing vessel. For the Quanti-Tray and Quanti-Tray/2000 systems, any sterile vessel can be used.

Store Pseudalert at 2–30°C away from light.

The Pseudalert reagent powder should be tan in color and free-flowing. If you have any concerns about the color or integrity of the powder, contact IDEXX Technical Services.

The mixing of sample and reagent can create foaming. IDEXX Antifoam Solution is needed to help the foaming subside before sealing the sample in the Quanti-Tray or Quanti-Tray/2000.