DNase I as a probe for unpolymerized actin: revisiting a classic tool for nuclear actin research

Actin is a key component of the cytoskeleton and also plays diverse roles within the cell nucleus. While polymerized F-actin can be detected using a wide range of probes, reliable methods to identify unpolymerized (“G-”) actin in fixed cells are relatively limited. Fluorescently labeled DNase I has long served as a high-affinity probe for monomeric actin and has recently gained renewed interest in nuclear actin research. Here, we briefly review established methods for visualizing actin in the cy