Searching the NCIMB catalogue for strains “equivalent” to those in other collections

There is some overlap between major culture collections, with most including a list of “equivalents” in their catalogues. Consequently, it is possible to search the NCIMB catalogue using strain numbers from other collections. NCIMB’s culture collection curator Dr Samantha Law takes a look at equivalency in strains, what it means, and how to find the cultures you are looking for…

The National Collection of Industrial, Food and Marine Bacteria includes thousands of strains isolated from all kinds of environments around the world – it is a much more diverse collection than you might expect from its name. While we do have many marine strains, and food related organisms, the collection also includes strains isolated from fresh water, soil and a host of other environments.

All culture collections give a unique identifier to each of the strains in their collections – and the format of this number is similar in the different collections around the world. The first part identifies the culture collection – e.g. “NCIMB” and the second part is the number for the specific strain. So for example, NCIMB 8295 is the unique identifier for a Pseudomonas aeruginosa strain held within the NCIMB collection.

There is some overlap between major culture collection holdings, where the same strain has been deposited in multiple collections. Many strains are stored in two or more public culture collections, as it makes the strains widely available to the global scientific community, and also acts as a back-up. This is good practice to insure against the risk of contamination or loss of viability – particularly important when you remember that culture collections are required to preserve and maintain cultures for decades – or even centuries! This overlap may have arisen because the person that first isolated the strain deposited it in more than one collection, but sometimes culture collections share strains too. If you are a regular user of our culture collection catalogue, you might have noticed that in some cases the depositor of the strain to the NCIMB collection was in fact another culture collection.

Culture collections share this information on equivalency, where it is known, and most publish a list of “equivalents” in other collections within their catalogues.

No culture collection can absolutely guarantee strain equivalency – errors occasionally happen, and in a very few cases, genetic drift may alter the properties of the strains between collections – but these are rare occurrences. It is generally accepted amongst major collections, that when a culture collection states that Pseudomonas aeruginosa NCIMB 8295 = NCTC 10332 = DSM 50071 = CECT 110, that these cultures will be indistinguishable from one another.

So, looking at our example of NCIMB 8295, when you look at our catalogue, you can see that 21 other collection IDs are listed in the strain entry, and the company that deposited the strain with NCIMB was the American Type Culture Collection.

In most cases, equivalency listings in our catalogue are in the format ABCD1234 i.e. there is no space between the culture collection identifier and the strain identifier. Consequently you can search for equivalents by selecting “Any text field” and “contains” then entering the identifier in this format to find the equivalent NCIMB strain. For example, searching NCTC10332 gives the search result NCIMB 8295 Pseudomonas aeruginosa. Searching the NCTC strain identifier alone e.g. 10332 returns the same result. Of course, if a strain identifier from another collection is the same as any other strain entry in the catalogue, searching without the culture collection identifier part may give more than one result, but it should be relatively easy to pick out the strain you are interested in.

If you are having difficulty using our catalogue at or you can’t find what you are looking for, you can always contact us at, and one of our culture collection staff will be able to check for you.

Dr Samantha Law