LabAutomation 2006 - SLAS

MP39
Yunseok Heo
University of Michigan, Ann Arbor
Ann Arbor, Michigan
yunsheo@umich.edu
LabAutomation2006
Co-Author(s)
Lourdes M. Cabrera
Gary D. Smith
Shuichi Takayama
University of Michigan, Ann Arbor
Preimplantation Embryo Development, Osmolality, and Its Relationship to
Polydimethylsiloxane (PDMS) Thickness
A microfluidic device has been devised that precisely controls fluid flow inside elastomeric capillary networks made of polydimethylsiloxane
(PDMS) by using multiple computer-controlled, piezoelectric, movable pins. However, this device needs a thin flexible PDMS platform.
When developing embryos into blastocysts on a PDMS microchip, the porosity of PDMS can induce osmolality changes in culture media
by evaporation. We characterized osmolality changes at different PDMS thicknesses and found an inverse relationship to PDMS thickness
and embryo development due to elevated media osmolality. We suggest using parylene-coated PDMS which has enough flexibility for use
with movable pin-controlled flow.
To form wells, 6.5 mm diameter holes were drilled into glass slides which were mounted on PDMS of 10, 1.0, 0.2 or 0.1mm thickness.
50 µl of Potassium Simplex Optimized Medium (KSOM) was added to wells, overlaid with oil, and assessed for osmolality at 24hr intervals.
KSOM osmolality in control drifted from 265+-5.1 to 281+-8.2 mmol/kg over 96 hours while KSOM osmolality increased from 265+-5.1 to
295+-5.4, 297+-10.7, 369+-9.3 and 447+-33.7 mmol/kg with the decreasing PDMS thickness, 10, 1, 0.2 and 0.1 mm, respectively.
To prevent these changes, parylene was coated on the outside 0.1mm-PDMS surface with 2.5 µm thickness. Parylene coated PDMS
osmolality shift over time was reduced, 265+-5.1 to 285+-1.2 mmol/kg compared to no parylene, and similar to controls. Percent
blastocyst development was significantly improved with parylene coating (87+-14 blastocyst development) compared to no parylene (2+-4;
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