Minispin rotor f45 12 11

The biofilm was grown in a polystyrene Petri dish for 24 h in static conditions at 37 °C and washed with PBS (pH 7.2) to remove planktonic cells. The biofilm was scraped off, nuclease-free water (1 mL) was added to the dish, and cells were transferred to a microcentrifuge tube and pelleted by centrifugation at room temperature at 13,400 rpm (MiniSpin^® Eppendorf—rotor F45-12-11) for 5 min. The pellet was resuspended with 100 μL of RNase-free water, 100 μL of a phenol: chloroform mixture at a 1:1 ratio was added, and the mixture was incubated at 70 °C for 30 min with shaking followed by centrifugation. The water fraction was then precipitated with isopropanol. Pellet was washed with 70% ethanol two times, air-dried, and resuspended in nuclease-free water. The concentration of RNA was measured by a NanoDrop (Thermo Fisher Scientific, Waltham, MA, USA).

Biofilms in a polystyrene Petri dish were grown and washed with PBS (pH 7.2) to remove planktonic cells. Nuclease-free water (1 mL) was added to the dish, and the biofilm was scraped off. Cells were transferred to a microcentrifuge tube and pelleted by centrifugation at room temperature at 13 400 rpm (MiniSpin^®Eppendorf—rotor F45-12-11) for 5 min. Each pellet was resuspended with 10 μL RNase free water, after which 100 μL of a phenol:chloroform mixture at a 1:1 ratio was added. The mixture was incubated at 70 °C for 30 min with shaking, followed by centrifugation. The water fraction was then precipitated with isopropanol, and the pellet was washed with 70% ethanol two times, air-dried, and resuspended in nuclease-free water. The concentration of RNA was measured by NanoDrop (Thermo Fisher Scientific, Waltham, MA, USA).