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Calcium flux

Non-Ratiometric Calcium Dyes

Fluo 3 and Fluo-4

Excitation of Fluo-3 is maximal 488nm and emission occurs at 530 nm. It is possible to use this dye to measure the calcium flux response in cells stimulated with an agonist or activating molecule. In the example below fluorescence intensity is on the y-axis and time is on the x-axis. A base line level of fluorescence is established in lymphocytes, monocytes and macrophage. The cells are then stimulated with different agonists and the change in fluorescence intensity recorded.

Fluo-4 has a better quantum efficiency than Fluo-3 can be used in a similar manner to Fluo-3.

Fluo-3/4 can be used in a ratiometric manner when used in conjunction with Fura-RED (Ex488 nm; Em 597 nm), which in contrast to Fluo-3 reduces fluorescence when bound to calcium. Ratioing the Fluo-3 and Fura-RED signals gives a ratiometric measurement of calcium.


Calcium flux

Use of Fluo-3

Use of Fluo-4

by Gary Warnes. © Queen Mary, University of London 2007
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