Calcium Green

high-resolution terminology - matching measurements at high-resolution

Calcium Green

Description

Calcium green denotes a family of extrinsic fluorophores applied for measurement of Ca²⁺ concentration.

Abbreviation: CaG

MitoPedia methods: Fluorometry 

Calcium green^TM is a registered trademark and available from Life Technologies (former Invitrogen) in several formulations. All fluorophores of the Calcium green family have the same fluorophoric moiety in their molecular structure and therefore near identical optical properties. They differ in their K_D values and are suitable for measuring different ranges of calcium concentrations.

• Calcium green 1: K_D = 190 nM
• Calcium green-2: K_D = 550 nM
• Calcium green-5N: K_D = 14000 nM

Measurement: See Calcium for method independent considerations related to measuring calcium levels, covering e.g.

• important consideration before starting a project involving calcium measurements
• Ca2+ buffering
• calculation of free Ca2+ concentrations
• Ca2+ calibration buffers.

See O2k-Fluorescence LED2-Module for specific aspects of fluorescence measurements using the O2k. On the fluorophores producers homepage detailed product information (| Long-Wavelength Calcium Indicators Product Information , |CalciumCalibration) as well as general information on measuring calcium (e.g. [1], [2]) is available.

The three Calcium green fluorophores and Magnesium green share the same fluorophore moiety in their molecular structure, therefore the optical properties are very similar and the same fluorescence sensor and filter set can be used. Since the used concentration of Calcium green might vary according to application, the optimum light intensity and amplification used may be different to those for Magnesium green. However, the values recommended for Magnesium green will provide a good starting point.

Signal and output

1. Signal: The O2k-Fluo LED2-Module is operated through the amperometric (Amp)-Channel of the O2k, with electric current (ampere [Amp]) as the primary signal.
2. Output: The focus of the output with Calcium green is on Type A: Concentration, and Type C: Force, potential.

More detail: » Signal and output

References:

• Use of Calcium green-5N with the O2k-Fluorescence LED2-Module: Elustondo 2014 Biochim Biophys Acta
• Anderson_2011_Am_J_Physiol_Heart_Circ_Physiol