Redefining Learning Disability Syndromes

Scientists at the West Midlands Regional Genetics Unit in the UK are using a Tecan HS 4800 Pro hybridization station to automate array-based comparative genomic hybridization (aCGH) for screening patients with learning disability and dysmorphology. The technique uses bacterial artificial chromosome (BAC) arrays, which are spotted with 3,200 genomic clones, allowing resolution of approximately 1 Mb and making it possible to identify previously undetected chromosomal abnormalities.

Dominic McMullan, Principal Clinical Scientist at the Unit, explained, We inject the probe onto the slides and leave them to be processed overnight, including automated washing and drying, so the slides are ready to scan next day and thats the beauty of the HS 4800 Pro! The systems segmented chambers allow us to do two separate hybridizations on one slide without any crossover. This is very important for aCGH, because we can test patient- and reference-labeled DNA in opposing fluorochromes on two different arrays, adding replicate confidence and removing any potential dye effects or bias. The HS Pro is easy to use and its inherent agitation makes the hybridization very even across the slide, increasing the signal to noise ratio. The agitation setting allows more viscous hybridization buffers to be used than previously, which is key, because aCGH buffers contain dextran sulfate.

Automating the process gives increased reliability and reproducibility, as well as maximizing our success rate. We are certainly detecting genomic changes that we would not have been able to pick up with previous methods, Dominic concluded.