Localizable and highly sensitive calcium indicator based on a BODIPY fluorophore

Anal Chem. 2010 Aug 1;82(15):6472-9. doi: 10.1021/ac100741t.


We introduce here a new class of BODIPY-based Ca2+ indicators which can be derivatized with biological ligands that permit the localization of the indicators in living cells. The underivatized BODIPY-based Ca2+ indicator (BOCA-1) shows a 250-fold increase in fluorescence intensity upon Ca2+ binding. We also prepared its O6-benzylguanine (BG) derivative, BOCA-1-BG, which can be covalently and specifically linked to SNAP-tag fusion proteins in living cells. The indicator retains its properties as a highly sensitive Ca2+ indicator after conjugation to proteins, displaying a 180-fold increase in fluorescence intensity upon Ca2+ binding. We further demonstrated that BOCA-1-BG through reaction with localized SNAP-tag fusion proteins can be used to sense changes in Ca2+ concentrations in the nuclei and in the cytosol of live CHO-K1 cells. The high sensitivity of the indicator together with the possibility to selectively couple it to proteins of interest makes it a powerful tool for measuring local changes in Ca2+ concentrations in living cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Boron Compounds / chemical synthesis
  • Boron Compounds / chemistry*
  • CHO Cells
  • Calcium / analysis*
  • Cricetinae
  • Cricetulus
  • Fluorescent Dyes / chemistry*
  • Glycine / analogs & derivatives*
  • Glycine / chemical synthesis
  • Glycine / chemistry
  • Guanine / analogs & derivatives
  • Guanine / chemistry
  • Indicators and Reagents / analysis
  • Microscopy, Fluorescence / methods*
  • Purines / chemical synthesis
  • Purines / chemistry*


  • 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene
  • Boron Compounds
  • Fluorescent Dyes
  • Indicators and Reagents
  • Purines
  • O(6)-benzylguanine
  • Guanine
  • Calcium
  • Glycine