Labeled calcium indicators are molecules that exhibit an increase in fluorescence upon binding Ca
2+. They have uses in many calcium signaling investigations, including measuring Ca
2+ in cells and tissues that have high levels of autofluorescence and also for detecting Ca
2+ release generated by photoreceptors and photoactivatable chelators. Cells may be physically loaded with the cell-impermeant salt forms of these indicators using patch pipette, microinjection, or our
Influx™ pinocytotic cell-loading reagent. The fluorescence signal from these cells is generally measured using fluorescence microscopy.
Learn more about ion indicators including calcium, potassium, pH, and membrane potential indicators ›Calcium Indicator (Cell-Impermeant Salts) Specifications:
• Label (Ex/Em of Ca2+–bound form): Rhod-5N (551/576 nm)
• Fluorescence intensity increase upon binding Ca2+: >100 fold
• Kd for Ca2+ in the absence of Mg2+, in buffer: ∼320 μM
• Exhibit fluorescence increase upon binding Ca2+ with little shift in wavelengthUsing TPEN to Control Heavy Metal Cations In addition, BAPTA-based indicators such as these bind various heavy metal cations (e.g., Mn
2+, Zn
2+, Pb
2+) with substantially higher affinity than Ca
2+. Perturbations to calcium measurements caused by presence of these ions can be controlled using the heavy metal-selective chelator
TPEN.
More Choices for Fluorescent Calcium Indicators We offer a large selection of Molecular Probes™ calcium indicators for use in various experimental scenarios. For more information, review
Fluorescent Ca2+ Indicators Excited with Visible Light—Section 19.3 in the Molecular Probes™ Handbook.
For UV-excitable Ca
2+ indicators, protein-based Ca
2+ indicators, conjugates of Ca
2+ indicators, and for fluorescence-based indicators of other metal ions (i.e., Mg
2+, Zn
2+) review
Indicators for Ca2+, Mg2+, Zn2+ and Other Metal Ions—Chapter 19 in the Molecular Probes™ Handbook.
For Research Use Only. Not for human or animal therapeutic or diagnostic use.
For Research Use Only. Not for use in diagnostic procedures.