Abstract: A method of synthesizing photolabile chelators as EDTA and EGTA derivatives to be used in caging multivalent cations is disclosed. The chelators chelate the cations forming non-biologically active compounds. The chelated compounds can then be localized in or near biological systems. Upon irradiation, the chelated compound cleaves with the subsequent cleaved remainders having a substantially lower affinity for the chelated cation. Large amounts of cation are thus rapidly released and the effect of such concentration jumps on the biological system can be accurately studied.