The March 2014 Special issue of Chemical Reviews has assembled some of the leading experts in the field with the goal of having them present the single molecule methods and their applications. Greene and colleagues in their article, explain that DNA often plays an active, dynamic role in directing the biological functions of DNA/protein complexes. Wuite and colleagues introduce optical tweezers as a complementary tool to probe DNA/protein interactions. They highlight the plethora of assays that have been developed to perform single molecule force measurements that quantify the mechanical properties of DNA. Ando and colleagues then introduce us to recent advances in atomic force microscopy (AFM) that have allowed them to directly image any biopolymer at near video rates without the need for attaching fluorophore labels or handles for tweezing. Transitioning into applications of single molecule tools, Bustamante and colleagues describe how a process as complex as transcription.