Re[2]: FL4/FACSCalibur
Wed, 13 Nov 96 18:52:47

As far as the use of tandem conjugates on the FACSCalibur system is concerned,
Tom Frey's message of 9/24 still holds?essentially that appropriate
experimental design will be key towards optimizing your results-especially
where sensitivity is concerned. So, direct excitation of PE-CY5 or other tandem
is not any more a "problem" on the Dual Laser FACSCalibur than the use of
multiple tandems would be on any system. Compensation will be required.

Indeed, the FACSCalibur System has been optimized for the use of FITC/PE/PerCP/
APC, but that does not preclude the use of many, many other types of
fluorochromes/dyes on this system. We have designed this system using a dual
laser approach to MAXIMIZE the flexibility and applicability. The PerCP/APC
combo was chosen to minimize the compensation required between FL3/FL4. But, as
you stated, a busy clinical lab could use alternative reagents on the system,
if they so desire.

Hope this helps clear up this issue.

Angela K. Schultz
FACSCalibur Program Manager/
Market Manager, Research

On Nov. 8, 1996, Jason Aaron wrote:

> Is it true that the Coulter will only work with
>tandem conjugates? Are there severe limitations to working with tandem dyes?
> Is a dual laser approach to 4 color a better option than single laser? What
>about 4 color reagents? Coulter is making claims of clinical use.

On Sept. 24, 1996, Tom_Frey wrote:

>Second, the system HAS inter-beam compensation. The compensation value for PE/
>Cy5 conjugates is quite high because of the direct red excitation of Cy5. I
>have used comp values like 60% on only one instrument - also only two PE/Cy5
>conjugates from only one vendor - "your mileage may vary". Very bright PE/Cy5
>conjugates could thus be a problem but dimmer ones seem OK. A strategy where
>the PE/Cy5 reagent subsets the APC-positives would be more robust than vice

It would appear the 'Calibur is able to directly detect APC, Cy5 or Cy7 as the
4th color. In that case the use of ANY of the PE tandems may present some
problems with the second laser. Of course this isn't a problem if you use PerCP
for your "near red" (FL3).

The instrument salespeople are fond of saying they make very little profit on
instrument sales and most of the profits are in the reagent sales; MAbs, etc..
Whether that's true or not, isn't the point. It's obvious the 'Calibur was
designed for use with PerCP. I wonder what the difference in price would be if
a busy clinical lab could substitute PE tandems for PerCP over a years time?

Just another factor in the decision making process.........


I've driven every kind of rig that's ever been made,
I've driven the backroads so I wouldn't get weighed......
(I don't know)

 Thomas Delohery                        | Internet:
 Manager, Flow Cytometry Core Facility  |    Phone: (212) 639-8729
 Memorial Sloan-Kettering Cancer Center |      Fax: (212) 794-4019
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 New York, NY    10021                  |

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