Nucleic acid-based diagnostic tests often require isolation and concentration of nucleic acids from biological samples. Commercial purification kits are difficult to use in low-resource settings due to their cost and insufficient laboratory infrastructure. Several recent approaches based on the use of magnetic beads offer a potential solution, but remain limited to small volume samples. We have developed a simple and low-cost nucleic acid extraction method suitable for isolation and concentration of nucleic acids from small or large sample volumes. The method uses magnetic beads, a transfer pipette, steel wool, and an external magnet to implement high-gradient magnetic separation (HGMS) to retain nucleic acid-magnetic bead complexes within the device’s steel wool matrix for subsequent processing steps. We demonstrate the method’s utility by extracting tuberculosis (TB) DNA from both sputum and urine – two typical large volume sample matrices (5-200 mL) using guanidine-based extraction chemistry. Our HGMS-enabled extraction method is statistically indistinguishable from commercial extraction kits when detecting a spiked 123-base DNA sequence. For our HGMS-enabled extraction method, we obtained extraction efficiencies for sputum and urine of approximately 10% and 90%, while commercial kits obtained 10-17% and 70-96% respectively. We also used this method previously in a blinded sample preparation comparison study published by Beall , 2019. Our manual extraction method is insensitive to high flow rates and sample viscosity, with capture of ~100% for flow rates up to 45 mL/min and viscosities up to 55 cP, possibly making it suitable for a wide variety of sample volumes and types and point-of-care users. This HGMS-enabled extraction method provides a robust instrument-free method for magnetic bead-based nucleic acid extraction, potentially suitable for field implementation of nucleic acid testing.
Shuangshen granules attenuate lung metastasis by modulating bone marrow differentiation through mTOR signalling inhibition.
September 7, 2020
Overexpression of MYBL2 promotes proliferation and migration of non-small-cell lung cancer via upregulating NCAPH.
March 23, 2020
Increased hippocampal shape asymmetry and volumetric ventricular asymmetry in autism spectrum disorder.
February 25, 2020
- ACC 2020The American College of Cardiology decided to cancel ACC.20/WCC due to COVID-19, which was scheduled to take place March 28-30 in Chicago. However, ACC.20/WCC Virtual Meeting continues to release cutting edge science and practice changing updates for cardiovascular professionals on demand and free through June 2020.
- CROI 2020Every year, CROI hosts some of the world's leading experts in HIV research, who come to present exciting new data and drive forward the field of HIV/AIDS research. This year, due to COVID-19, CROI held their meeting virtually.