Optical Tweezers and Applications in Single Molecule Force Spectroscopy

Optical tweezers are versatile tools used to trap and manipulate small objects with sizes typically within the range of micro to nanometers. Basically, the technique consists of a highly focused laser beam that is used to exert forces on the objects in a non-invasive way. In this talk we will discuss the main characteristics and applications of optical tweezers, with emphasis on single molecule force spectroscopy - an approach in which one can use the tweezers to stretch single isolated macromolecules such as proteins, nucleic acids and others, obtaining their elastic behavior from where many information can be extracted. In particular, we will show that this type of experiment is sufficient to determine both the binding modes and the complete physical chemistry of DNA interactions with ligands such as proteins, drugs, dyes, surfactants and others.