Frequently Asked Questions

Actero™ Enrichment Media

General Information, Use and Applications

1. What is the difference between Actero™ Elite Enrichment Media and Actero™ Universal Enrichment Media?

2. What is Actero™ Elite Enrichment Media?

3. Why would I use Actero™ Elite?

4. Has Actero™ Elite been validated by independent certifying organizations?

5. How long is the enrichment incubation period for Actero™ Elite?

6. How many Actero™ Elite products are available?

7. Who would use Actero™ Elite or Actero™ Universal?

8. What packaging formats can Actero™ Elite or Actero™ Universal be purchased in?

9. How do I get a sample of Actero™ Media?

10. Can Salus customize packaging of Actero™ media to fit my facility’s requirements?

11. Can I schedule automatic shipments of Actero™ Media to make sure I do not run out of material?

12. How do I obtain Actero™ Technical Data Sheets, Safety Data Sheets (SDS), Product Information Sheets or Certificates of Analysis?


Preparation/Reconstitution, Sampling and Storage

1. What grade of water should I use to reconstitute the dehydrated (powder) Actero™?

2. What are the recommended storage conditions for Actero™?

3. What is the shelf life of the product once it has been opened?

4. Does light affect the performance of the medium?

5. Why should the Actero™ medium be stored in cold and dark conditions, yet after when applied to a sample, it needs to be warmed up?

6. How do I protect the medium from light?

7. How long is the enrichment incubation period for Actero™ Elite?

8. The Actero™ Listeria Enrichment Media has been left at room temperature overnight. Could this affect its performance?

9. The package inserts for Actero™ Listeria Enrichment Media specifies that the medium should be pre-heated to 29, 32, 35 or 37 degrees C. How long can the media stay pre-heated?

10. I am preparing the Actero™ Elite Listeria Enrichment broth (FMC-022). The preparation instructions say to autoclave the 1L at 110 degrees C for 15 minutes. What would the time be to autoclave a 3L container?

11. What are the best conditions for preparing Actero™ Salmonella Enrichment Media?

12. Can I supplement the Actero™ Salmonella Enrichment Media several days prior to utilization and how long can it be stored afterwards?

13. At what point does the malachite green get added to the Actero™ Salmonella Enrichment Media?

14. After the Actero™ BPW ISO EZ-Media Dry Bag is re-hydrated, for how many days is the product good for?

15. How long can Actero™ Multiplex (SAL/CR) be stored on the lab bench after rehydration?


Quality Control (QC)

1. Do Actero™ enrichment mediums conform to ISO?

2. Is Actero™ performance QC tested?


Performance and Appearance Issues

1. Is there a stable, target pH value for the prepared Actero™ Listeria media?

2. We observed a little deposit in our 5L Actero™ Elite Listeria MediaBox™. Is this normal?

3. We notice a little precipitate in the bottle after preparing the Actero™ Salmonella Enrichment Media. Is this normal? Does this affect the performance of the media?

3. Over time in using the Actero™ Elite Salmonella Enrichment Media, we have seen this type of precipitate variation from lot to lot. Is this common and to be expected?

4. Sometimes we observe an insoluble film or precipitate after autoclaving (110 degrees C for 15 minutes) the media. Is there any way to avoid this? Does this affect the performance of the media?


General Problem Solving


Glassware Cleaning

  • Is your glassware clean?
  • Are there no residues or visible particles?
  • Are you using a dishwasher?
  • Did you verify that your dishwasher is working well?
  • Did you wash the bottle by hand and then use it to prepare the medium?
  • Have you tried another dishwasher?
  • Have you tried another lot of detergent when you washed the glassware?
  • Did you rinse your glassware after washing?


  • Did you use the appropriate water? (Type 2 water is good)
  • Did you verify the conductivity of the water when you took the water from the system?
  • Did you try water from another source to prepare the medium?
  • Are you using reservoirs to store water and are the reservoirs clean?


  • Did you verify that your autoclave is properly working?
  • Did you try to sterilize the medium with a different autoclave?