The director of the lab responsible for the DNA breakthrough in the Kerry Babies investigation has explained how advancements in technology allowed scientists to build a complete DNA profile of Baby John from a sample taken 34 years ago.
Dr Geraldine O’Donnell, director of DNA at Forensic Science Ireland, said it had stored since 1984 dried blood from a sample, taken from the baby, to allow newer techniques to shed more light on the case.
“It was submitted in 1984 and, at that time, Forensic Science Ireland was able to do what we call blood grouping tests on the sample.
“Following that work Joanne Hayes would have been excluded as the mother of Baby John, and the blood sample would have been dried at room temperature and put into storage,” Dr O’Donnell explained.
“The practice actually at the time was that we would have transferred some of the blood onto a piece of cloth that would have been stapled to piece of cardboard, and why we did this was to keep the sample in anticipation of technical developments, because DNA profiling was just beginning to be discovered at that point in time,” Dr O’Donnell explained.
“So we kept that sample on file until we were asked subsequently by the Garda Serious Review Team to look to see whether it would be now possible with the new developments in DNA to actually generate a DNA profile.
“That is the stage now where we have got to; where we now have a DNA profile from Baby John which is available for comparison to a mother or a father and indeed siblings of Baby John,” she said.
Dr O’Donnell told Today with Sean O’Rourke on RTÉ Radio 1 the timing of the latest development was due to two factors: the advancement in technology and the request from the gardaí, which came towards the end of 2017.
“We introduced DNA profiling for forensic testing in Forensic Science Ireland in the early 90s and, in those days, we required significant quantities of DNA, and for it to be a high quality, but now we can actually go back to very old samples that have been sitting around for quite a period of time because the technique has got very much more sensitive and we can actually deal better with DNA that is isn’t actually of good quality which would have been the case in these samples,” she said.
“We couldn’t keep the blood sample for 34 years.
“It would have degraded or broken down quite significantly, so the practice at the time for all our cases would have been that we would have taken some of that blood and dried it onto a piece of cotton cloth.
“Doing that the drying effect would give it the best chance of lasting for a longer period of time and then we would have kept it and frozen it to enhance the ability to have it when required for old cases that need to be revisited.”
Dr O’Donnell said current DNA profiling “allows for certitude when you’re determining the parentage of an individual” and that statistical methods allow it determine any sibling relationships, albeit with lesser certainty.
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