Inconsistent cell counts and distribution during acquisition
When following run time vs event length (or other parameter), often it can be observed that as the run progresses the number of events acquired (either cells or beads) drops. Moreover, the cells are not distributed evenly – large ones focus at the beginning of the run and gradually “lost”.
Attached please find images for illustration:
https://drive.google.com/folderview?id= ... sp=sharing
This phenomenon is more pronounced when using a 3ml loop for example, but very evident with the 0.5ml loop or with the autosampler, regardless of re-suspension and agitation prior to injection into the loop.
Accordingly, sample acquisition is not homogenous (inconsistent) and the results may be biased (heavily depending on the duration the sample has been left in the loop and the critical time of acquisition start, delay, and the washed out leftover at the end).
I think this happens due to gravimetric settling of the cells which sinks to the leading front of the loop.
I would appreciate your insight regarding this matter and its possible effects on the data acquired.
Sincerely,
Dr. Tomer Meir Salame
Flow Cytometry Unit
Biological Services Department
Weizmann Institute of Science
Wolfson building, basement 1, room 21
P.O. Box 26, Rehovot 7610001, Israel
Tel: ++972-8-934-2721 / 2235
Mobile: ++972-57-5489307
Fax: ++972-8-934-4194
E-mail: tomer-meir.salame@weizmann.ac.il
http://wws.weizmann.ac.il/Biological_Se ... etry-about
Head, Mass Cytometry Unit
Life Sciences Core Facilities
Weizmann Institute of Science
E-mail: tomer-meir.salame@weizmann.ac.il
https://www.weizmann.ac.il/LS_CoreFacil ... etry/about