• Home
  • Search Results
  • Calcium rubies: a family of red-emitting functionalizable indicators suitable for two-photon Ca2+ imaging.

Calcium rubies: a family of red-emitting functionalizable indicators suitable for two-photon Ca2+ imaging.

Journal of the American Chemical Society (2012-07-24)
Mayeul Collot, Christina Loukou, Aleksey V Yakovlev, Christian D Wilms, Dongdong Li, Alexis Evrard, Alsu Zamaleeva, Laurent Bourdieu, Jean-François Léger, Nicole Ropert, Jens Eilers, Martin Oheim, Anne Feltz, Jean-Maurice Mallet
ABSTRACT

We designed Calcium Rubies, a family of functionalizable BAPTA-based red-fluorescent calcium (Ca(2+)) indicators as new tools for biological Ca(2+) imaging. The specificity of this Ca(2+)-indicator family is its side arm, attached on the ethylene glycol bridge that allows coupling the indicator to various groups while leaving open the possibility of aromatic substitutions on the BAPTA core for tuning the Ca(2+)-binding affinity. Using this possibility we now synthesize and characterize three different CaRubies with affinities between 3 and 22 μM. Their long excitation and emission wavelengths (peaks at 586/604 nm) allow their use in otherwise challenging multicolor experiments, e.g., when combining Ca(2+) uncaging or optogenetic stimulation with Ca(2+) imaging in cells expressing fluorescent proteins. We illustrate this capacity by the detection of Ca(2+) transients evoked by blue light in cultured astrocytes expressing CatCh, a light-sensitive Ca(2+)-translocating channelrhodopsin linked to yellow fluorescent protein. Using time-correlated single-photon counting, we measured fluorescence lifetimes for all CaRubies and demonstrate a 10-fold increase in the average lifetime upon Ca(2+) chelation. Since only the fluorescence quantum yield but not the absorbance of the CaRubies is Ca(2+)-dependent, calibrated two-photon fluorescence excitation measurements of absolute Ca(2+) concentrations are feasible.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
1,2-Bis(2-Aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, 98%
Sigma-Aldrich
1,2-Bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, ≥96.0% (HPLC)

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

MilliporeSigma

Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.