Fluorescent indicators have long been used to measure intracellular Ca²⁺ levels, an important process in many signaling activities. In a recent Science paper, Robert Campbell’s laboratory at the University of Alberta describe an improved screening method for detecting changes in Ca2+ dependent fluorescence that they used to develop improved genetically encoded Ca²⁺ indicators, dubbed GECOs. The green (G-GECOs) demonstrate a two-fold improvement in Ca²⁺-dependent change in fluorescence over earlier fluorescent protein Ca²⁺ indicators. Blue-shifted (B-GECO) and red-shifted (R-GECO) Ca²⁺ indicators fill a void in the spectrum of available colors for genetically encoded Ca²⁺ indicators. By recombining these newly created constructs, additional ratiometric GECOs, GEM-GECO and GEX-GECO, were developed. The GECO plasmids offer researchers additional choice and flexibility when selecting fluorescent Ca2+ indicators.
Plasmid reagents are available at Addgene, the non-profit plasmid repository