55
OCTOBER 16-18, 2011 • PORTLAND, OR
P19
RELIABLE FLOW CYTOMETRIC DETECTION
OF TARGET POPULATIONS AT EXTREME LOW
FREQUENCIES
Ruud Hulspas, Don F Perrault, Emanuel TM
Machado, John C Sharpe
Cytonom/ST, LLC, Boston, MA, USA
With acquisition speeds of 50,000 to 100,000
events per second, high-speed analysis with fow
cytometers has made a signifcant contribution to
assays that depend on rare-event detection. As a
result, enumeration of various stem cell phenotypes
and nucleated red blood cells is practical and precise
in most routine analysis methods. Nevertheless,
cross-contamination and acquisition time (i.e.
sample throughput) limit the ability to perform
reliable measurements on samples that contain
target populations at frequencies lower than 1 in
100,000. A practical approach to create a cross-
contamination free analysis is disposable microfuidic
chip technology allowing each sample to be run
through a newly replaced fuidic system. Sample
throughput can be increased by parallel processing.
We designed and tested a disposable microfuidic
chip that provides increased throughput over
conventional fow cytometers by splitting the fuid path
into parallel fow channels. For analysis, we built a
system capable of parallel detection and processing
of event rates exceeding 200,000 events per second.
A disposable fuidic system incorporating the chip was
utilized to allow samples to be analyzed without cross
contamination, thus permitting statistically reliable
rare event analysis within short acquisition times.
Using mixtures of fuorescent and non-fuorescent
particles, we were able to reliably detect a 0.001%
target population measured within a three minutes
acquisition period. As such, this parallel technology
can be useful in studies where reliable measurements
of extremely rare target populations (e.g. endothelial
cells and circulating tumor or fetal cells) are important.
POSTER ABSTRACTS