Chromatographic profile at 280 nm obtained when filtering DMEM medium supplemented with 10% FBS on the QSD device.

<p>The y-axis represents the absorbance at 280 nm (red line) and the y2 axis the pH value (blue line). The x-axis is the volume (mL) of growth medium passed through the QSD device. FT: flow-through. AU: absorbance unit</p

Experimental design for assessing the impact of the QSD filtration of growth media on cell growth.

<p>Three flow-through fractions (FT1, FT2, FT3) from the QSD column have been obtained and tested either individually, or after pooling (F1+F2; F1+F2+F3) to determine their capacity to support cell growth. Details of the procedure are described in the Material and Methods section.</p

Western blotting of DMEM medium supplemented with 10% FBS and spiked with the 263K strain of scrapie.

<p>(A) Analysis of the spiked starting material, prefiltrate, and filtrate (flow through) fractions 1 and 2 of Run 2 (B) Analysis of filtrate fractions 3 and 5 of Run 2. MW: molecular weight; SSM: spiked start material; kDa: kilodalton; PreF: pre-filtrate sample; QSD-F1/F2/F3/F5: filtrate fractions 1/2/3/5; Pos. Cont.: Positive control. (N = 2).</p

Cell viability assay at day 5 of BHK-21 (A), Vero (B), CHO (C), and HEK293 (D) cells.

<p>Cells were grown in DMEM medium supplemented with 10% FBS without filtration (C) or following QSD filtration (FT1, FT2, FT3, FT1+FT2; FT1+FT2+FT3). FT: flow-through. Mean +/- SD (N = 3).</p

Sodium dodecyl sulfate electrophoresis under nonreducing conditions.

<p>Molecular weight protein markers (left lane); start growth medium (C); flow-through (FT) and eluate (E) of QSD-filtered FBS and growth media (DMEM, MEM, and F-12K) containing 10% FBS. Total protein content in each lane was 20 μg. kDa: kilodaltons</p

Morphology of HEK293 cells.

<p>Cells were grown in DMEM medium supplemented with 10% FBS without filtration (C) or following QSD filtration (FT1, FT2, FT3, FT1+FT2; FT1+FT2+FT3) FT: flow-through. The scale bar represents 100 μm.</p