Extracting, storing and distributing DNA for a birth cohort study

Abstract

Issues surrounding DNA extraction from biological samples are discussed, together with details of storage and distribution methods. The benefits of laying down immortalised cell lines are described.

Choosing the types of biological sample to collect in longitudinal birth cohort studies

“…Birth provides a unique opportunity to collect biological samples from the child in the form of cord blood, umbilical cord and possibly the placenta. These samples provide an opportunity to measure markers of fetal exposure, and cord blood and maternal blood samples are ideal for establishing a DNA or immortalised cell line collection 2 . If births take place predominantly in hospital maternity units, coverage of the study population can be higher at birth than at any other time.…”

“…As we have indicated, 1 there are good reasons for collecting biological samples: as a way of validating questionnaire or other information; to estimate exposure to environmental contaminants; to provide a source of DNA; 2 and as a way of measuring outcome traits and intermediary phenotypes. The key question then is which samples should be collected.…”

“…Citrate buffer is used for samples that are to be used as a source of viable cells, for example for Epstein‐Barr viral transformation of lymphocytes as a source of DNA 2 . However, the volume of citrate buffer that needs to be added makes measurement of analyte concentrations in the residual fluid inaccurate and this anticoagulant is therefore unsuitable for the general run of blood samples collected over the lifetime of a study.…”