DMNPE-caged ATP is a nucleotide analog in which the terminal phosphate is esterified with a blocking group, rendering the molecule biologically inactive. Flash photolysis of the caging group with UV illumination at 355 nm results in a rapid and highly localized release of the free nucleotide at the site of illumination. The DMNPE caging group absorbs light more efficiently than CNB and NPE caging groups at ~360 nm, but photolysis rates and quantum yields are generally lower.