RE: 50 mW violet laser

Hi all,
 
Interesting question! I've never given this issue much thought myself, much less experimented around with it, but wouldn't, say, a neutral density filter between laser and cuvette resolve the issue (theoretical - I'm not sure the right grade filter is available to cut a 50mW output down to 25mW)? That would allow you to "upgrade" your machine instantly to greater laser output should you need it for a specific application as well. Or am I missing something?
 
thanks,
 
Guy

________________________________

From: Dunaway, Dave [mailto:Dave.Dunaway@nationwidechildrens.org]
Sent: Wed 16-Apr-08 4:06 PM
To: cyto-inbox
Subject: 50 mW violet laser



Flowmeisters, 

	In an effort to create redundancy across a couple of our LSR II's we are looking at the addition of a 405 violet laser to one that lacks such.  One of the machines that does have a violet laser has a Coherent 25 mW.  In a quote the we received from BD they specified a 50 mW laser.  When asked about the fact that we wanted the 25 mW version the response we received was that they weren't sure if they still offered a 25 mW version.  That aside, this situation has raised a couple of questions that I am hoping someone on the listserve could address.

	Our rationale for wanting the 25 mW rather than the 50 is that higher power of the 50 will create a greater difference in signals generated, thereby moving away from our goal of redundancy across machines.  While no two machines will ever be exactly the same, and proper controls and data analysis would be paramount we want to be prepared to allow our users to switch between machines in the hopefully rare case of there being no other choice.  In your opinion does the use of a 50 vs a 25 create more potential disparity than both machines having 25's?

	Secondly, does anyone out there have experience with the 50 mW laser?	Is it more problem prone?  I guess the general question would be what are the pluses and minuses both in terms of performance and reliability with regard to the stronger laser?	Thanks in advance for your input.

Dave 






David Dunaway 
Flow Cytometry Core Laboratory 
The Research Institute at Nationwide Children's Hospital 
700 Children's Drive 
Columbus, Ohio 43205 
(phone) 614-355-2820 
Dave.Dunaway@nationwidechildrens.org 

________________________________

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