Pvdf hydrophilic millex hv sterile syringe filter unit 0.45 micron

Five F. tularensis strains of subsp. tularensis Nevada 14 and subsp. holarctica LVS, Kato, Yama, and Kf Water were prepared to validate the effective inactivation of F. tularensis. Bacteria were heated at 94°C for 3 min and 56°C for 30 min, filtered using Millipore PVDF Hydrophilic Millex-HV Sterile Syringe Filter Unit 0.45 Micron (SLHV033RS, EMD Millipore Corporation) and 0.22 Micron (SLGV033RS, EMD Millipore Corporation), incubated at 4°C for 24 h with detergents (1% LDS buffer, 1% NP-40, and 1% TritonX-100), and radiated at room temperature (23°C) with a low-pressure lamp (254 nm). These procedures were in accordance with the same conditions as those for the treatment of F. tularensis SCHU P9. The CFU of untreated and treated samples were compared. The experiments were conducted in four replicates.

Fifty microliters of F. tularensis SCHU P9 (average, 2.9 × 10⁶ CFU/ 100 μL) suspended in 1 mL of CDM was screened through Millipore PVDF Hydrophilic Millex-HV Sterile Syringe Filter Unit 0.45 Micron (SLHV033RS, EMD Millipore Corporation, Billerica, MA, USA) and 0.22 Micron (SLGV033RS, EMD Millipore Corporation). Before and after filtration, the samples were serially diluted and cultured on Eugon chocolate agar plates at 37°C for 4–7 days. The average CFU number in 100 μL was calculated from the average number of colonies of four replicated samples.