Re: Problems with Time Delay on FacsAria

I'm in agreement there. If clogging is not an issue then your most  
likely culprit is the pressure regulator or perhaps the seal around  
the agitator motor on the platform that holds the sample. have you  
been having any problems with "sweetspot" stability also? Could point  
to pressure leaks.
It is highly unlikely in a stable system for the delay to change  
during the course of a run especially.

If your laser is dipping out you would find that you have to crank up  
the voltage but the delay should not change.

Wayne A. C. Harris


On Mar 9, 2008, at 5:28 PM, Haviland, David L wrote:

>
> Two immediate items leap to mind based on my experience with an  
> LSRII and Aria.
>
> 1)  Inconsistent sheath pressure.   If if is fluctuating in any  
> way, this will throw off
> the delay.
> 2)  Power fluctuations in the lasers. This will make events appear  
> "dimmer" than they
> actually are and if not enough power is delivered, you won't see  
> events at all.
>
> David
>
>
>
> -----Original Message-----
> From: Zhang, Yan [mailto:yan.zhang@ahus.no]
> Sent: Fri 3/7/2008 9:54 AM
> To: cyto-inbox
> Subject: Problems with Time Delay on FacsAria
> Hi flowers:
>
> I have recently had some confusing problems with Time Delay, there  
> are 2 lasers(blue and
> red) on our Aria, it happened after a service while the red laser  
> has bees adjusted for
> getting more narrow peaks.
>
> The Time Delay was ok for a while, then it began to behave badly,   
> like today, I was
> calibrate for QC, the Time Delay was set on -38.45, the  
> compensations were performed
> successfully afterwords, and I ran some stained blood/lymphocytes  
> to check the
> compensations, it was ok, then I continued to run some samples,  
> then suddenly there were
> no signals.
>
> After a while with shutting down, cleaning in suspicion of clogging  
> in	the system, I
> checked with the rainbow 8 peaks beads, the Time Delay has  
> decreased to - 40,45.
>
> This has happened couple of times before, I got really confused.  
> Every flowccytometrist
> knows that it takes hours for preparing calibration and  
> compensation, with this kind of
> problems of mine, one could sit for working in hours.  I wonder if  
> some experts could
> explain the problems.
>
> Not only so, I found out that theTime Delay and area scaling of red  
> laser are associated
> with each other. My experiences is that it's not easy to get a  
> strong signal of APC-H and
> APC-A, the mean values changes all the time if I adjust the Time  
> Delay by a given area
> scaling. If I change the area scaling value, then the Time Delay  
> changes too,	the
> changes are about ±1.
>
> So my second question is how I can get a proper Time Delay and a  
> area scaling of Red
> laser.
>
>
> Sincerely yours
>
> Yan Zhang
>
> Senior engineer
> Flow-lab
> Epi-Gen Inst.
> Akershus univercityhospital
> Norway
> Tel. 67984432/67984622
> Mobil. 48053728
>
>
>
>
>
>
>
>