Instrumentation

LSR II

Description

This instrument is equipped with three diode pumped solid-state lasers (Blue-488nm, Green-534nm, Violet-408nm and a Red-633nm). The Green (Coherent-Compass) laser is unique and has a total laser output of 150mW, while all other lasers are low energy 25mW lasers. As shown at top of figure 7 (Figure 7. Laser Path and Octagon of the LSR II) (PDF), each laser line can be independently adjusted through a series of steering mirrors. The lasers are set in the following delay timing order, blue, violet, red and green with the blue laser as the reference laser. The bottom right shows the octagon assembly for detection of the green laser-excited emissions. This unique collection system is composed of a series of photomultiplier tubes (PMT's) and optics in an octagonal arrangement. Photons enter this system and are systematically reflected to the next detector by a dichroic mirror or transmitted through a band pass filter and counted in that PMT. Each detector quantifies light principally, but not solely, from a single fluorochrome.

Figure 7. Laser Path and Octagon of the LSR

The geometry of this instrument is based on recent advances in light optics and far-red sensitive collection detectors (PMT). These instruments use optical fibers to transmit photons of light from the laser-excited conjugates are transmitted through optical fibers and measured in unique optical arrays. The flexibility of these systems allow for the current design with 18 fluorescent detectors and two physical parameters. This current optical design (Figure 8. Filter Configuration) (PDF), shows the dichroic mirrors and band-pass filter arrangement. This configuration allows for 2 fluorescent detectors dedicated to blue laser excitation, 5 fluorescent detectors dedicated to green laser excitation, 8 fluorescent detectors dedicated to violet laser excitation and 3 fluorescent detectors dedicated to red laser excitation. Note the configuration nomenclature for the detectors is listed in table 2 below. This uses the excitation laser (G=green laser, B=blue laser, R=red laser and V=violet laser) and the peak detection location (660nm for the APC channel) as the detector name (e.g. APC detection would be measured in R660).

Figure 8. Filter Configuration

 Table 2. Detector Configuration and Nomenclature

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