STOCK CONTROL AND PERIODIC QUALITY CONTROL

LABORATORY PROCEDURES FOR MICROORGANISMS

REFERENCE NO.: M/1998/3.02

TITLE: STOCK CONTROL AND PERIODIC QUALITY CONTROL

Irrespective of the applied preservation method all preserved stocks are monitored for viability of the strains and the number of available ampoules, capillary tubes or straws. In this way it is ensured that strains are not lost and that cultures for dispatch are always available. Flow charts describing the general procedure of monitoring the strains are attached [M/1998/3.02 Appendix 1 to Appendix 3].

STOCK CONTROL

An adequate stock control system must be in place (e.g. registration of viability, purity and, where appropriate, identity). If the number of preserved ampules becomes low (i.e. below a number of ampules defined by the collection) a new preservation batch of the strain is planned.

When the collection is large, or when there is a high turn-over, it is advisable to implement a computerised stock control system.

M/1998/3.02 Appendix 8 gives an example of a note for entering into the stock/delivery datafile.

PERIODIC QUALITY CONTROL

After storage each culture should be inserted in the "maintenance plan" (i.e. a scheme for periodic control of the preserved cultures) of the collection. Several aspects determine the frequency of control of the culture (e.g. the type of the organism, the preservation method, turn-over of the strain, etc.).

At least viability, purity and where appropriate identity of the strains has to be tested. For bacteria and yeasts, examples of methods used in detecting the number of surviving cells or the overall viability are described in M/1998/3.02 Appendix 4. An example of procedure for estimating the survival rates for fungi is given in M/1998/3.02 Appendix 5.

The result of the tests has to be registered (e.g. on protocol forms, available for the different types of preservation; for examples see M/1998/3.00 Appendix 5.01, M/1998/ 3.00 Appendix 5.05.1 and M/1998/3.00 Appendix 5.08.2).

The proposed date of the next viability test is registered in a computer database or in a viability check book (see M/1998/3.02 Appendix 6 for an example).

The viability of the strain will be tested on the proposed date. If the viability is low, a new batch of preserved cultures has to be prepared. To plan this, a preservation book can be used. An example is given in M/1998/3.02 Appendix 7.

Guidelines prepared for CABRI by DSMZ, CBS and BCCM, 17 May 1998
Page layout by CERDIC
Copyright CABRI, 1998

© The CABRI Consortium 1999 - 2023
This work cannot be reproduced in whole or in part without the express written permission of the CABRI consortium.
Site maintained by Paolo Romano. Last revised on February 2023.