Why and how to use a biological specimen bank in epidemiological and clinical research: Methodological issues

The use of biological specimen banks has proliferated in the last decade of scientific research. The present paper analyzes some issues that need to be taken into consideration by those researchers who carry out studies using biochemical determination as a measure, for example, of exposure and disease definition. Relevant considerations regarding specimen banking at very low temperatures (lower than -70°C) for a long time (years) include conditions and temperature of storage. Cryogenic containers (liquid nitrogen tanks and mechanical freezers) are described in terms of their potential advantage and disadvantage for biological specimen bank long term storage, freezing conditions (slow and fast freezing) and storage units are also described in terms of suitability of their use in specimen banks. One of the main aims of a biological specimen bank is to preserve specimens for future determinations to test hypotheses which at the time of the specimen bank establishment are not yet conceived or for which there are not suitable laboratory techniques. As a consequence, special attention should be paid by researchers to some important issues when designing a specimen bank. The choice of what to store, where to store, and how to store has a critical influence on the development and future scientific use of a biological specimen bank.