Burst-Integrated Fluorescence Lifetime BIFL Experiments

1 Burst-Integrated Fluorescence Lifetime (BIFL) Experiments 

Far better burst resolution was obtained by TCSPC modules with an internal sequeneer. The sequeneer reeords a virtually infinite sequence of decay curves in time intervals of 100 ps and shorter (Fig. 3.9, page 36) [31, 163, 500]. A part of a sequenee reeorded this way is shown in Fig. 5.125. 

Histograms for a solution of Cy5-dCTP flowing through a microcapillary are shown in Fig. 5.126. The integration time per step of the sequence was 0.5 ms. The total number of steps was 204,800, resulting in a total acquisition time of 102.4 seconds. 

Burst-recording in the continuous-flow mode can be eombined with multidetector operation. The detectors can be used to record the fluoreseence in different wavelength intervals or under different angles of polarisation. This multiparame-ter detection technique delivers the lifetime, the angle of polarisation, the fluorescence anisotropy, and the emission wavelength within the individual bursts [442, 500]. 

For a burst resolution around 1 ms, detection by the eontinuous flow mode is relatively efficient in terms of data size. The drawbaek of the eontinuous flow mode is that the burst resolution is limited by the increase of the data size and, and eonsequently, by the available data readout rate (see Fig. 5.127). 

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