Time correlated single photon counting (TCSPC)
Installation allowing fluorescence lifetime measurements
We have added another piece to the cryobench toolbox, by installing Time-Correlated-Single-Photon-Counting (TCSPC) device on the cryobench microspectrophotometer.
Steady-state fluorescence spectra and fluorescence decay histograms can be recorded simultaneously. Reliable measurements can be obtained either from protein crystals or nanolitre-sized protein solution drops.
Setup
• A pulsed laser diode - Wavelength: 440nm – Optical power: 1,14 mW at 40 MHz – pulse duration: <300ps at 1mW, <90ps at 0.3mW (Picoquant GmbH)
• A photomultiplier (PMA-M, Picoquant)
• An acquisition board (TimeHarp 200, Picoquant)
• A LabView control and monitor interface
Possibilities & Limitations
Possibilities |
Limitations |
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Very sensitive to subtle changes in the environment of the fluorophore |
Only usable if the protein contains a fluorophore |
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Excellent for studying fluorescent proteins |
For the moment only 440nm exciting laser available |
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Able to probe crystals as well as nanolitre drops |
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Temperature controlled TCSPC experiments on crystals, for detection and trapping of intermediate states |
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