Open AccessExtension and denature temperature of dsDNA molecules at various magnetic forces by using magnetic tweezers
Author(s) -
Chung YungChiang,
Tsai ChengWei,
Lin ShihHao
Publication year - 2016
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2015.0388
Subject(s) - magnetic tweezers , electromagnet , magnetic field , magnet , materials science , gauss , magnetic force microscope , elasticity (physics) , analytical chemistry (journal) , chemistry , nuclear magnetic resonance , physics , composite material , molecule , magnetization , chromatography , organic chemistry , quantum mechanics
Stretching experiments on lambda‐deoxyribonucleic acid (DNA) were carried out in microfluidic channel using a microscope, micro‐flow pump, and electromagnet. The micro‐flow channel was fabricated by using micro electromechanical technology, and the electromagnet was analyzed by software to simulate the magnetic field distribution. The magnetic field was 248.6 gauss at a current of 0.5 A, and the system could exert 20.4 pN of force on a magnetic bead with diameter of 2.8 μm. When the buffer temperature was 25 °C, the average length of lambda‐DNA molecules was 1.9 μm without magnetic field. In a magnetic field of 248.6 gauss, the extension was 7.2 μm, the total length was 9.1 μm, and the coefficient of elasticity was 2.83 × 10 −6 N/m. When the buffer temperature was 45 °C, the average length was 4.6 μm without magnetic field. At 45 °C in a magnetic field of 248.6 gauss, the extension was 11.9 μm, the total length was 16.5 μm, and the coefficient of elasticity was 1.71 × 10 −6 N/m. Besides, the denature temperature of dsDNA decreases with increasing magnetic force, and the temperature difference can be higher than 7 °C. This system can be used to measure the related properties of macromolecules.