Researchers detected single nucleotide polymorphisms (SNPs) tied to osteoporosis risk from a drop of blood, in a 15-minute, inexpensive test using an investigational electrochemical device.
10-uL finger-prick blood samples from 15 people were diluted 1:5 and subjected to rapid thermolysis (30 seconds at 95 degrees C) to extract the DNA.
Blood samples with the lysed DNA, and negative controls, were applied to an investigational, generic, portable electrochemical device (Labman Automation, UK), in which individual gold electrodes were covered with reverse primers for each of five osteoporosis-associated SNPs.
DNA in the blood samples that matched the SNPs bound to these electrodes, and the reaction was amplified with recombinase polymerase labeled with ferrocene, which facilitates electrochemical detection.
Five SNPs associated with an increased risk of developing osteoporosis and risk for fracture were detected in the 15 blood samples, and the results were validated using TaqMan SNP genotyping assays and Sanger sequencing.
Measuring bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) reliably predicts fracture risk, but only when a significant amount of bone is already lost.
Researchers developed and validated a generic, battery-operatable, portable device (Labman Automation, UK) to detect osteoporosis-associated SNPs from a fingerpick blood sample, with no need for DNA extraction or purification.
The entire assay from the addition of the thermolyzed blood sample to the readout of the results was complete in just 15 minutes, with a cost per SNP, on a laboratory scale, including the cost of the electrode array and all reagents, of 0.3 euro (0.33 USD).
The researchers previously showed that the device identified an SNP associated with rifampicin resistance in Mycobacterium tuberculosis in a sputum sample, and an SNP linked with cardiomyopathy in blood; they plan to test a scaled-up version of the device.
“The platform is completely generic and has immense potential for deployment at the point of need in an automated device for targeted SNP genotyping with the only required end-user intervention being sample addition,” say the authors in their report.
The authors, from INTERFIBIO Research Group, Tarragona, Spain, as well as Austria, the Czech Republic, and the Netherlands, published their findings in ACS Central Science.
The researchers did not report any study limitations.
The study received no commercial funding. The authors report no relevant financial relationships.
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