BALF samples were placed immediately on ice, filtered with 0.2-µm syringe filters (SFCA Fisher Scientific, Pittsburg, PA), and stored at −80°C for future analysis.
The IgG-Sepharose was rapidly and thoroughly washed on a scintered glass filter with ice-cold PBS- 5 mM EDTA and bound proteins were eluted with ice-cold CAPS buffer (50 mM CAPS, 1 M NaCl, 5 mM EDTA, pH 11.0 to 11.2).
After 24 h incubation, which had been shown earlier not to affect cell viability, CM was collected, placed on ice and filtered through a 0.2 μm filter to remove cell debris.
Two to 3 days after transfection, the supernatant was collected on ice and filtered though a 0.45 µm cellulose filter.
The reaction was terminated by addition of 3 ml of ice-cold filter wash buffer and rapidly vacuum filtered through glass fiber filters (Whatman GF/C).
Gangster films were already in vogue, thanks to the success of Josef von Sternberg's "Underworld" (1927), but they flourished when sound introduced the sensational elements of chattering machine guns, screaming tires and, most important, the varied timbres of contemporary American speech, bursting with vivid idioms ("Aw, go slip on the ice!") and filtered through every accent known to man.
The mixture was poured into 400 ml ice water, filtered, and the solid was washed with water.
By melting the ice and filtering the water, they collected more than 3000 micrometeorites, tiny particles from space that were 10 microns in diameter or larger.
Finally the phages were precipitated by incubation on ice of filtered supernatants with 0.25 volumes 20% PEG6000/2.5 M NaCl followed by centrifugation (13,000× g, 30 min, 4°C).
Hydrolysate samples were mixed with 69.7 μL of 72% sulfuric acid in 10 mL screw-cap culture tubes and incubated in a 121°C bench-top hot plate for 1 hour, cooled on ice and filtered into HPLC vials.
