title: Single-molecule studies using magnetic traps.
abstract: In recent years, techniques have been developed to study and manipulate single molecules of DNA and other biopolymers. In one such technique, the magnetic trap, a single DNA molecule is bound at one end to a glass surface and at the other to a magnetic microbead. Small magnets, whose position and rotation can be controlled, pull on and rotate the microbead. This provides a simple method to stretch and twist the molecule. The system allows one to apply and measure forces ranging from 10(-3) to >100 pN. In contrast to other techniques, the force measurement is absolute and does not require calibration of the sensor. In this article, we describe the principle of the magnetic trap, as well as its use in the measurement of the elastic properties of DNA and the study of DNA-protein interactions.
authors.forename: Timothée
authors.initials: T
authors.lastname: Lionnet
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Allemand
authors.forename: Andrey
authors.initials: A
authors.lastname: Revyakin
authors.forename: Terence R
authors.initials: TR
authors.lastname: Strick
authors.forename: Omar A
authors.initials: OA
authors.lastname: Saleh
authors.forename: David
authors.initials: D
authors.lastname: Bensimon
authors.forename: Vincent
authors.initials: V
authors.lastname: Croquette
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004548:Elasticity; D008280:Magnetics; D008863:Microspheres; D011485:Protein Binding
chemical_list: D004247:DNA