5,5'-Dimethyl BAPTA tetrapotassium salt | CAS 73630-09-8

5,5'-Dimethyl BAPTA tetrapotassium salt is a cell-compatible calcium chelator built on the BAPTA scaffold, widely used in fluorescence-based calcium biology to control intracellular Ca2+ levels during imaging and assay development. By tightly binding Ca2+, it helps researchers define Ca2+-dependent signal behavior, calibrate fluorescent readouts, and minimize variability from residual or fluctuating calcium in buffered systems. Its tetrapotassium salt form supports aqueous workflows commonly used with fluorescent indicators and microscopy/plate-reader experiments.

1. Calcium Imaging Calibration

5,5'-Dimethyl BAPTA tetrapotassium salt is frequently used to set and stabilize low-Ca2+ conditions when calibrating fluorescence Ca2+ indicators for microscopy or plate-reader measurements. Researchers add the chelator to buffered imaging media to reduce background Ca2+-dependent fluorescence and to standardize starting conditions across experiments. This enables more reliable interpretation of stimulus-evoked Ca2+ dynamics in cultured cells, primary cells, and reconstituted systems.

2. Fluorescent Assay Signal Control

5,5'-Dimethyl BAPTA tetrapotassium salt supports fluorescence assay workflows where Ca2+ is a required cofactor or trigger for indicator response. In kinetic assays, the chelator is used to suppress Ca2+-driven signal prior to initiating reactions, helping separate Ca2+-dependent readouts from non-Ca2+ contributions. Assay developers commonly incorporate it into buffer recipes for reproducible baseline control in high-throughput screening formats that rely on Ca2+-sensitive dyes.

3. Intracellular Ca2+ Buffering

5,5'-Dimethyl BAPTA tetrapotassium salt is used to buffer intracellular calcium perturbations during mechanistic studies of Ca2+-regulated signaling. Experimentalists employ it to dampen transient Ca2+ spikes or to clamp Ca2+ to a defined level, improving the interpretability of downstream fluorescence reporters that respond to Ca2+. This is particularly valuable in experiments combining Ca2+ indicators with other fluorescent readouts, where Ca2+ crosstalk can otherwise confound quantification.

4. Reconstituted System Studies

5,5'-Dimethyl BAPTA tetrapotassium salt is also applied in in vitro and reconstituted biochemical systems where controlled Ca2+ concentrations are required for reproducible fluorescence behavior. Researchers use the chelator to tune free Ca2+ in reaction buffers for Ca2+-dependent enzymes, binding assays, and indicator-based monitoring of Ca2+ availability. This approach helps ensure that observed fluorescence changes track the intended Ca2+ parameter rather than uncontrolled carryover from buffers, salts, or experimental handling.