Freeze-drying your bacterial strains

Lyophilisation, also known as freeze-drying, is a preservation method achieved through dehydration. NCTC has over 50 years experience of freeze-drying bacterial strains and has collated a large viability data set which supports the suitability of freeze-drying for prolonged storage.

We offer a bespoke freeze-drying service using our specialised equipment and expertise to scientists who want to preserve their own bacterial or fungal cultures.

This service can:

• contain bespoke customer bacterial strains

• be used for research and development purposes

• be for category 2 or 3 bacterial strains

• be cheaper - the ampoules are stable at ambient temperature and no fridges, freezers or ice shipping is required

• lead to enhanced reproducibility and reliability

• decrease the risk of contamination – instant resuscitation and less pipetting

Cultures can be preserved using this method in one of two formats:

Glass ampoules 

Microbial cultures are freeze-dried in glass ampoules flame-sealed under vacuum. This format is suitable for long term preservation of cultures, for example; using this method, members of the Enterobacteriaceae family will survive for more than 50 years and most anaerobic organisms will survive for approximately 20 years.

Customers may specify the number of ampoules required, in multiples of 10 (up to 180) and can choose their own identifying number for the sample, up to a maximum of 12 characters. Clients should agree the number of ampoules and the information to be included on the label at the earliest stage, so that the ampoules can be prepared prior to receipt of the culture to be freeze-dried. Cultures of Hazard Category 3 can also be accepted for freeze-drying, but the charges are higher to reflect the extra work and precautions necessary to prepare the ampoules in a containment facility.

Capped vials

An alternative to ampoules, is to freeze-dry cultures in vials with a rubber closure held in place by a crimped foil, easy-opening cap. These are much easier to open than glass ampoules, however, cultures maintained in such vials may remain viable for only about two years.

This format is therefore highly appropriate for specimens for EQA scheme distributions, where significant numbers need to be produced for dispatch to multiple scheme participants, and where long term storage is not required.

Clients may select the number of vials required in multiple of 100 (up to 500) and can choose their own identifying number for the sample, up to a maximum of 12 characters. Clients should agree the number of vials and the information to be included on the label at the earliest stage, so that the vials can be prepared prior to receipt of the culture to be freeze-dried.

Contact us with your requirements to obtain a quote and information on how to submit samples.