Zinc concentrations in the 1–100 nM range are routinely measured using fluorescent indicators nominally designed for Ca2+ detection, but higher Zn2+ concentrations are present in synaptic vesicles and released in response to electrical stimulation or excitotoxic agonists.

We’ve developed a number of Molecular Probes® ion indicators to track zinc with intense fluorescent signals and a range of wavelength options.

Select zinc indicators ›

Indicators for Zinc

  • Optimized for higher Zn2+ concentrations
  • Compatible with multiple analysis platforms

FluoZin™ dyes are unique indicators designed for detection of Zn2+ in the 0.1–100 µM range with minimal interfering Ca2+ sensitivity. They provide bright signals for assaying exocytotic release of Zn2+ from pancreatic β-cells after stimulation with glucose or potassium. Zn2+ concentrations can be measured using imaging platforms, cell-based microplate assays, or flow cytometry.


BioProbesHuman vascular smooth muscle cell loaded with FluoZin™ indicator and stained with Hoechst 3342.

Zinc Indicators Selection Guide

Used for spatial and temporal resolution of Zn2+ concentrations.

ReadoutResponds to Zn2+ concentrations in synaptic vesicles with increasing fluorescenceResponds to saturating levels of Zn2+ with 50-fold increase in fluorescence emission
Range0–100 µM range with minimal interfering Ca2+ sensitivityLow nM to µM range with minimal interfering Ca2+ sensitivity
Standard filter setFITC
Ex/Em (nm)495/515494/516
Cell permeant or impermeant?ImpermeantPermeantImpermeantPermeant
Usage notesLoad by microinjection, patch pipette, or pinocytic loading agentLoad in cell mediaLoad by microinjection, patch pipette, or pinocytic loading agentLoad in cell media
Format500 µg50 µg500 µg100 µg
Cat. No.F24180F24181F24194F24195