Quantitative PCR can be an expensive technique but, says Geoff Simmons, incorporating automated pipetting brings significant savings in staff time and reagent costs
The BioAnalysis team at LGC, the UK’s leading independent analytical laboratory, uses real-time PCR techniques to analyse DNA extracted from a variety of sources, such as bacterial cells and foods. The introduction of an automated liquid handling system has saved staff time, reduced PCR reagent costs and enabled projects to be completed within shorter timescales.
Founded over 150 years ago as the Laboratory of the Government Chemist, LGC has been an independent, privately owned company for the past ten years. Services provided by LGC’s facilities include chemical, biochemical and forensic analysis, DNA testing and genetic screening. LGC’s BioAnalysis team is based at the company’s head office in south west London. This group uses real-time PCR technologies in areas such as GM analysis, gene expression and microbial trace detection, and also undertakes the development of international standards and reference materials.
Dr Gavin Nixon is a senior researcher in the BioAnalysis team at LGC: “As well as offering bioanalytical diagnostics and consultancy, our team provides contract research services for various companies and government-funded programmes. For example, a recent DTI-funded project in the personal care/clinical research sector required rapid characterisation of bacterial populations present within clinical samples. This large-scale study involved detecting indicator microbes and generating high quality quantitative data, in order to make comparisons between real-time PCR and standard microbiological techniques.”
Over 500 clinical genomic DNA samples had to be screened for three key bacteria by quantitative real-time PCR, using an Applied Biosystems 7900HT Fast Real-Time PCR System. The timely delivery of this project was dependent on the use of a complementary liquid handling system.
Gavin Nixon explained: “Manual plate set-up of a 96-well format was not an option because of the limited time available for the study and the need to reduce reagent costs, save staff time and maintain experimental design flexibility. Automatic pipetting would remove the variability associated with manual set-up, particularly when multiple users are involved, but needed to be extremely precise in order to deliver the highly reproducible data we required. The team undertook a comprehensive evaluation of various different liquid handling systems and finally selected Eppendorf’s epMotion 5075 LH, based on its flexibility, pipetting accuracy at extremely small volumes and very user-friendly software.”
Through the integration of the epMotion 5075 LH system into assay set-up processes and the high throughput capabilities of their real-time PCR instrument, the team was able to dramatically reduce the expected screening study time (excluding the assay development stage) from one or two months down to only two weeks.
Nixon said: “Time is the most expensive input in our work, and therefore time-saving is the most important advantage of automated pipetting, which we use for plate set-up, reagent and sample template transfer and in preparing serial dilutions for standard curves. Moving from 96 to 384-well plates means not only can we screen more samples but we can access more complex experimental designs which can only be performed automatically, for example incorporating randomisation. With single or multichannel tools and accurate pipetting of volumes as small as one microlitre, the system gives us the flexibility to reduce sample volumes and the associated costs. Significantly, the advantages of automation are combined with increased reproducibility of results and high quality data output – which is vital for the services LGC delivers.”
As quantitative PCR techniques become more and more widely used, automated pipetting offers a way for laboratories to maximise the potential of their investment in real-time PCR instrumentation. Reducing reaction volumes brings significant savings on reagent costs, while time saved on setting up PCR assays can be devoted to tasks such as designing experiments and evaluating results, and projects can be completed much more quickly.
By Geoff Simmons. He is Brand Marketing Specialist at Eppendorf UK