Decrease in MFI using HTS on LSRII

Kateryna Lund klund at usuhs.mil
Tue Jun 12 11:09:13 EDT 2007


Dear Andrew

We had a similar problem when we ran beads on our LSRII with and without HTS. Eventually,
we realized that the problem was caused by bubbles that formed when HTS was connected to
LSRII. We were able to solve this problem by priming several times and by being very
careful when connecting HTS to LSRII. Now, the beads that we run with HTS look just as
good as the ones without it. The same goes for the samples run by our users.

I hope that this input will be helpful to you.

With kind regards,

Kateryna Lund


Kateryna Lund
Flow Cytometrist
Biomedical Instrumentation Center
Uniformed Services University of the Health Sciences
4301 Jones Bridge Road, Room G230
Bethesda, MD 20814-4799
Phone: 301-295-3666
Fax: 301-319-8218
Email: klund at usuhs.mil

>>> "Morschauser, Andrew" <andrew.morschauser at roche.com> 6/5/2007 11:27 AM >>>
Dear Group,


I am posting the following question for a colleague:


Here is my question for the Flow cytometry group.



I have been trying to develop a plate based assay to measure a
cell-surface antigen on CHO cells using the LSRII-HTS system.


I perform the staining in 12X75mm polypropylene tubes.	At the end of
the staining procedure, I transfer to polystyrene tubes and the mean
fluorescence of intensity is determined on the LSRII-HTS system.  I then
take that same sample, transfer to polypropylene or polystyrene U-bottom
96-well plates and re-analyze the samples using the HTS system.


The MFI of the samples analyzed in the tubes is > than	the MFI of the
samples analyzed in the plates?  It is the same sample.

Shouldn't the MFI's be relatively the same?


 I would like this to be a plate-based assay because there are quite a
number of samples to be evaluated but I don't feel comfortable with the
plate-based results.


Any hints or suggestions would be greatly appreciated.	



Sincerely,


Andy Morschauser






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