Getting and LSR

[Franco]

We are planning on getting a new LSR with 5 lasers from BD: We like the Fortessa version because of the small size... hower... it seems less expandable (will only fit 5 lasers) compared to the LSR II (that will fit 7 lasers)... Aside from the blue (3pmt), red (3pmt), violet (8pmt) and UV lasers (2pmt) we have to choose between a Green (532) and the yellow green (561) lasers offered? We would be greatful for information that would help us with these choices....
Manuel Franco

[farmer]

Hey Franco,

As your probably aware, a lot of this decision will be guided by the panels you plan on running. The ability to expand is always good, especially if you'll be incorporating larger panels and simply need more colors. I don't know much about the Fortessa, other than that a few people have had issues with the 561 nm laser being used by BD.

Its been shown that both a 532 and 561(using a longer filter) are superior to a 488 for PE detection. This information comes from Bill Telford at the NIH/NCI. Here is a quote from him:

"We’ve done some comparisons between 532 and 561 nm lasers for PE detection, which are also included in the linked document. 561 nm lasers at 50 mW improve PE sensitivity somewhat when compared to 532   
nm at the same power level using our new 590/20 nm filter – this is not too surprising if you look at the PE excitation spectrum, which peaks around 556-560 nm. The 561 nm laser also likely excites less cellular autofluorescence, which will also improve the signal-to-noise.  But no one with an existing 532 nm install should panic and replace it with a 561 nm just for PE detection! This comparison did not look at higher power levels, since (until recently) 50 mW was the highest power level available at 561 nm.   532 nm lasers applicable for flow can exceed 200 mW, which would presumably improve sensitivity. But 561 nm lasers are now available at 100 mW,   
and higher power units are coming, so they should be comparable in power to the green very soon. But also keep in mind that laser wavelength and power are only part of the equation – the laser must be properly integrated and aligned into your system, or you will get suboptimal performance even with optimal excitation."

Hope that helps!

RF