Pluronic f127 surfactant

The inner surfaces
of the coverslips were dealt with 0.2% w/v nitrocellulose (Sigma-Aldrich)
and 0.03% w/v polystyrene particles (ACME microspheres) in alcohol
and then heated at 150 °C for 5 min.^{31 (link)} The nitrocellulose was slightly melted and polystyrene particles
were fixed on the surface as reference beads. Anti-digoxigenin (10
mg/mL, Sigma-Aldrich) was used to treat the surface overnight at 37
°C. Then the surface was dealt with a passivation buffer [10
mg/mL bovine serum albumin (BSA), 1 mM EDTA, 10 mM pH 7.4 phosphate
buffers, 10 mg/mL Pluronic F127 surfactant (Sigma-Aldrich), 3 mM NaN₃] at room temperature for at least 4 h, to avoid nonspecific
adherence of beads to the surface. The DNA constructs were diluted
to 50 pM, and mixed with 2× diluted Dynabeads MyOne with a volume
ratio of 1:1. The mixture was injected to the flow cell for DNA tethering.
After 15 min, the untethered DNA constructs were rinsed away.

Initially, 1.0 g of triblock copolymer Pluronic F127 surfactant (Sigma-Aldrich)
was added to a solution containing 15 mL of deionized water and 60
mL of 2 M HCl at 313 K with stirring until the copolymer was dissolved.
At that point, 3.20 mL of tetraethyl orthosilicate (TEOS, Acros Organics)
was added and stirred for 12 h at 313 K. The mixture was moved to
a sealed container and heated to 373 K in an oven for 20 h. The resulting
white precipitate was filtered, washed with water and ethanol, and
dried at 338 K overnight. Finally, the copolymer was removed by calcination
in air at 823 K for 3 h.