A new human genetic resource: a DNA bank established as part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC)

We describe a unique human DNA resource forming part of the Avon Longitudin al Study of Pregnancy and Childhood (ALSPAC), a longitudinal cohort study i nvolving 14 000 children and their families living in a geographically defi ned area of England. The DNA bank will underpin the search for associations between genetic polymorphisms and common hearth outcomes. The opportunitie s to collect blood samples suitable for DNA extraction are necessarily limi ted, and the samples themselves have often been treated in different ways a nd have varied storage histories. With the need to maximise yields, the cho ice of DNA extraction method is critical to the success of the bank and we have investigated the suitability of various commercial and in-house method s of DNA extraction. Various steps have been taken to minimise errors in sa mple address and identification, including the use of a pipetting robot for dilution and transfer of samples between 96-well arrays to provide aliquot s suitable for PCR. The robot has been programmed to cope with concentrated viscous DNA solutions.