46 THE SCIENTIST | the-scientist.com
Fluidic Analytics Fluidity One
Mission Bio Tapestri Precision
Genomics Platform
Launched last December, the Tapestri Preci-
sion Genomics Platform was the first high-
throughput instrument for single-cell DNA
sequencing sample prep. Using droplet-
based microfluidics technology, Tapestri
first exposes cells to a protease that lyses
the nucleus and frees the DNA from its con-
densed chromatin formation. Heat then dena-
tures that protease before the system adds
the reagents to amplify the loci of interest
and to barcode them according to their cell of
origin, readying the samples to be fed into a
next-generation sequencer.
“It’s exciting,” says MD Anderson Can-
cer Center geneticist Nick Navin, whose
group has used the instrument regularly for
about a year to detect the combinations of
mutations found in individual breast cancer
cells. “That allows you to really understand
the genetic substructure of a tumor,” hesays, as well as “to reconstruct the
evolution of the mutations.”
Tapestri can prep up to 10,000
cells simultaneously, compared with
only 384 when sorting cells into wells
of a plate. Moreover, says Navin, the
instrument takes only about a day to
prepare a sample, compared with five
to seven days using the plate method.
The Tapestri costs $79,500,
and consumables run about $795
to $1,300 per sample. Mission Bio
offers several fixed panels that target
loci relevant in various cancers, and
can develop customized panels that
target up to 300 loci of interest, and
possibly more in the future, expanding Tap-
estri’s applications beyond oncology, says
Dennis Eastburn, chief scientific officer at
Mission Bio.WILEY:“This new microfluidic platform for
high-throughput single-cell DNA sequencing
could be a powerful approach for analyzing
tumor cell heterogeneity and understanding
the mechanistic basis of tumor evolution."Among the many potential applications
of Fluidity One is “routine biophysics,”
says Sean Devenish, the head of R&D at
Fluidic Analytics, which makes the protein-analysis instrument. Devenish envisions
labs routinely using the instrument for
quality control, testing protein-containing
solutions when they first arrive and again
when they come out of the freezer to make
sure the contents haven’t degraded. Users
pipet 5 μL of sample onto a disposable
microfluidic chip, then insert it into the
benchtop Fluidity One instrument. The
sample runs through a chamber in parallel
with a stream of buffer, into which proteins
diffuse. The instrument measures the rate
of this diffusion to calculate the average
size of the proteins; it also measures
sample concentration.
Alex Büll, who studies protein aggrega-
tion in disease at the University of Düsseldorf
in Germany, says he’s found Fluidity One
useful for analyzing urine samples from
patients. “It’s very difficult to actually estimate
the concentrations properly, so we use theFluidity One to determine the concentrations,
and we also follow the aggregation of the
proteins and the dimer/monomer equilib-
rium,” he explains. Fluidity One’s advantage
over measuring light scattering (a standard
technique for determining the size of pro-
teins in solution) is that light scattering
results are dominated by any aggregates
in the solution, while Fluidity One delivers
a “true average” size value for the proteins
present, Büll says. Devenish adds that the
instrument can also reveal whether proteins
are bound to each other or to DNA, lipids,
or nanoparticles.
Fluidity One costs $30,000, plus chips
and reagents, which cost about $5 per run.ZHANG:“Characterizing and performing
quality control on purified proteins is critical
for consistent results. This tool could be a great
addition to any biochem lab.”