Frequently Asqued Questions - FAQ

MAKING AN ORDER

FREEZE-DRIED SAMPLES


MAKING AN ORDER

How can I make an order?

Orders can be made from the CECT via fax (+34 96 354 31 87) or e-mail (orders@cect.org). You must always indicate:
  • The scientific name of the microorganism requested.
  • The CECT strain number. It is not necessary to put it if you are not interested in one particular strain.
  • Contact person and their telephone number.
  • Type of format for each strain. In the event this is not indicated, it is understood that you wish to receive it as a freeze-dried sample.
If you are a first-time customer you must also include and attach the following information:
  • Name of the Centre or Company.
  • Tax/VAT number.
  • Complete postal address to which the strains are to be sent (including the country for deliveries outside Spain).
  • Telephone number.
  • Fax number.
  • e-mail (if applicable)
  • Address to which the invoice should be sent if it is different to that for delivery.
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How long will it take for me to receive the strains?

It depends on the availability of the strain at the moment of ordering.
If the strains are available, the delivery period will be around one week from moment the order and the documents required for despatch (form for risk group 2, phytosanitary passport, etc.) are received at the CECT.
Otherwise, the CECT will notify the user, offering the possibility of choosing another strain of the same species that is available, to speed up delivery.

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How can I pay?

Together with the strains we attach an invoice for the corresponding amount. At the bottom of the invoice you will find information regarding the CECT bank account with the account number to which you should make the payment. It is also possible to pay for strains or the other services offered by the CECT via a nominative cheque made out to the “Colección Española de Cultivos Tipo (CECT)”. On the back of the invoice is the material transfer agreement (MTA) of the CECT, which indicates the maximum term in which to pay invoices issued by the CECT.

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Which strain should I choose?

In the CECT catalogue, which is available on-line and enables searches to be carried out, there are more than 8000 strains, belonging to different genera and species.
If you have no preference for a specific strain, just convey the name of the species to the CECT, and we will send you the most common strain available of the requested species.

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How many different formats do the CECT microorganisms come in?

Currently there are three formats for the microorganisms supplied by the CECT, which are:
  • Freeze-dried samples.These represent the traditional format used for the strains in the CECT. They are glass ampoules in which the microorganisms have been subjected to a freeze-drying process, which involves the sublimation of the water in which they are suspended after freezing. The strains preserved like this can be kept viable for many years, provided that they are kept under proper storage conditions and also depending on the type of microorganism. To open the freeze-dried sample, we recommend you to follow the instructions attached to the strains and you can also down-load information here in PDF.
  • Active Growth. This is a culture of the microorganism requested in the culture medium suited to its growth. In this case, no recovery method is necessary because the microorganism is already physiologically active and ready to use.
  • Acticult 3R. It is the most modern format of the CECT strains. The aim of this format is to help the user to prepare the back up batches of the CECT strains, by supplying them with a tube of the requested strain in active culture and three cryovials with a protective solution so that the user can prepare a back up batch by him/herself, which must be kept at -20°C.


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FREEZE-DRIED SAMPLES

How should I store the freeze-dried sample until it is opened?

In the CECT the freeze-dried samples are kept at 18°C or 5°C depending on the type of microorganism they contain. In the case of bacteria and filamentous fungi with small spores, the recommended storage temperature is 18°C and when dealing with yeast and filamentous fungi with large spores, they are stored at 5°C. In all cases it is of the utmost importance to keep the freeze-dried samples away from the light, stored inside dark boxes or bags, and above all to avoid oscillations in the temperature. In this respect it is preferable to store any freeze-dried sample in a fridge at 4°C for some weeks than to leave it in the laboratory where it will be subjected to temperature changes.

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How should I open the freeze-dried sample?

The instructions for opening the freeze-dried samples are sent together with the strains in all dispatches from the CECT, although you can also download them from the following link: Instructions to recover freeze-dried samples

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The silica gel stone in the freeze-dried sample is pink/yellow

The freeze-dried samples from the CECT contain a humidity indicator to detect possible infiltrations of air in the tube during their preservation. This indicator is a stone of silica gel with a colour marker that changes according to the level of humidity. In the CECT we used silica gel with a dye based on cobalt blue that is blue when it is dry and turns pink on getting damp. However, to fulfil the new normative regarding materials and the environment, we have changed the type of silica gel, the colour of which is more environmentally friendly and gives off a reddish colour when dry and a yellowish/amber colour when humid. Whenever you detect a silica gel colour indicating humidity, it indicates that the vacuum seal of the tube has been broken; consequently it is almost certain that the strain stored there is no longer viable. If this loss of vacuum in the tube is observed within the 30 days of the guarantee established in the CECT material transfer agreement (MTA), you can request the CECT to send a replacement tube without any additional cost, by filling in the claim/complaint form for strains, which is sent with the orders and that can also be filled in on-line at the following link: Form for claims/complaints about strains

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I am unable to get the freeze-dried sample to grow. Why?

When no growth is observed from the freeze-dried sample, it could be due to a number of causes:
  • The freeze-dried sample is out of date or stored at a variable temperature and/or in the presence of light. In these cases it is possible that the microorganism has degraded as a consequence of the storage conditions.
  • The resuspension of the freeze-dried sample has been done too quickly and a homogeneous suspension has not been obtained from it. The rehydratation of the strain has not been done properly, which has caused its lack of viability.
  • The incubation temperature does not coincide with that recommended in the CECT catalogue. You must always conform to the culture conditions recommended by the CECT in our catalogue of strains (in the printed version or in the on-line version), which are optimum for the growth of the microorganismos. The CECT will not assume any responsibility in the event other culture conditions are used.
  • The culture medium used is not that recommended by the CECT. See the previous point. On the other hand, you should bear in mind that selective or differential media should never be used to recover the strains from the freeze-dried sample, as these are under stress and so it is necessary to use optimum conditions to achieve complete recovery of their proper metabolic functioning.
  • The growth time used is not enough for the microorganism. You should take into account that each strain has a growth time that is mainly characteristic of its species. In general, the bacterial strains will grow in 24 or 48 hours, while yeasts need from two to seven days to grow and in the case of filamentous fungi time periods of around a week are common.


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Can I resuspend the freeze-dried sample in peptonated water?

At the CECT we always recommend freeze-dried samples to be recovered directly in the culture medium recommended for each one of them, so that they are under conditions with the proper nutrients from the beginning. However, it is possible to suspend the freeze-dried sample with peptonated water or with a sterile physiological solution provided that as soon as the homogeneous suspension of the organism has been obtained it should be inoculated in the culture medium recommended by the CECT for that strain and incubated at the temperature indicated in each case.

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Can I save some of the freeze-dried powder without resuspending it?

Absolutely not. The reason for this is that as soon as you open the glass ampoule that contains the freeze-dried sample, the vacuum is lost, and the powder of the freeze-dried sample, which is very hygroscopic, starts to absorb water from the atmosphere, thus the cellular structures rehydrate and, as they are not in an optimum culture medium, the cells die and become unviable.

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Can I save some of the suspended freeze-dried sample to use it later?

It is not possible to save some of the freeze-dried sample to use it later, as the cells of the microorganism are stressed and can only be recovered by incubating them in the suitable culture medium at the optimum temperature. The rest of the suspension that is left in the tube should be inoculated onto fresh culture medium or thrown away after being autoclaved.

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How long does the freeze-dried sample last unopened?

The length of time that the freeze-dried microorganisms can remain viable depends, to a great extent on two main factors. One factor concerns the microorganism itself. There are strains that are more resistant than others and can withstand long periods of time that can reach some tens of years. However, there are others that can hardly remain viable for some months. Storage is the other factor influencing the viability of the strains preserved in tubes as freeze-dried samples, i.e. the conditions under which they are stored. The microorganisms must be kept at a stable temperature (see FAQ number one, concerning freeze-dried samples) and away from the light.

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What is the expiry date of the freeze-dried samples?

The expiry date of the freeze-dried samples from the CECT is ONE year from the moment they leave our installations. However, according to our material transfer agreement (MTA), the CECT does not assume any responsibility for claims/complaints about the strains over 30 days after despatch. It is also possible for strains to remain viable for longer if they are stored properly.

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How can I preserve the microorganism once it has grown?

There are different methods of preserving microorganisms, as well an extensive specialized bibliography in this respect. In the section "Services" of our web you will find a section with an extensive related bibliography.

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How many CFU does each freeze-dried sample have?

We do not know. At the CECT we do not quantify the freeze-dried samples once the process has been completed. Viability and authenticity are checked in each new batch, but not quantity. Nevertheless, we can state that in our freeze-dried samples there are between 106 and 108 CFU in practically all the strains.

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