GFP expression in Vero cells induced by ricin with and without milk.

<p>GFP transduced Vero cells were treated with increasing concentrations of ricin in milk. After incubation of Vero cells with Ad-GFP and ricin for 3 days, GFP expression was quantified fluorometrically. Error bars represent standard errors. (n = 3).</p

Quantitation of viral DNA in transduced Vero cells.

<p>Vero cells transduced with Ad-CMV-GFP were treated with 1 µM AFB1, 1% milk, or 1 ng/ml ricin. The PCR product for the 167 base pairs amplicon was quantified by qPCR. Error bars represent standard errors. (n = 3).</p

Increased GFP expression in Vero cells in the presence of low concentrations of AFB1 and ricin.

<p>Vero cells transduced with Ad-CMV-GFP were treated with increasing concentration of AFB1 (A) or ricin (B) toxins. GFP expression was quantified fluorometrically. Error bars represent standard errors. (n = 3).</p

Effect of milk on recombinant gene expression in Vero cells.

<p>A series of increasing concentrations of reconstituted milk were incubated with transduced Vero cells with Ad-CMV-GFP. GFP expression was quantified fluorometrically (A) or by analysis of individual cells by flow cytometry. (B). Milk at a concentration of 1% dramatically increased the recombinant protein transcription. Note the shift in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071682#pone-0071682-g003" target="_blank">Figure 3B</a> in the number of cells exhibiting higher cellular fluorescence. (n = 3).</p

Milk enhances the expression of β-galactosidase and luciferase enzymes.

<p>Control transduced Vero cells (without milk) (5A) and cells with 1% milk (5B) were incubated for 24 h. The cells were then fixed with glutaraldehyde followed by addition of x-gal solution. After 10 min incubation, the cells were analyzed by bright field light microscopy ×200 magnification. Vero cells transduced with Ad-CMV-Luc (5C) with and without 1% milk were incubated for 24 h. After addition of substrate, the relative light units (RLU) emitted were measured with a luminometer. Vero cells with and without 5% milk were transduced with Ad-CMV-LacZ or Ad-RSV-LacZ (5D) and RLU were then measured after addition of substrate. Error bars represent standard errors. (n = 3).</p

Induced GFP expression in Vero cells pre-incubated for 48 h with unheated or heated AFB1.

<p>A series of increasing concentrations of unheated or heated of AFB1 were incubated for 48 h with Vero cells. The cells were then transduced with Ad-CMV-GFP for 48 h. GFP expression was quantified fluorometrically. Error bars represent standard errors. (n = 3).</p

Strains used to generate toxoids.

<p>Strains used to generate toxoids.</p

Detection of Stx in group beef samples spiked with STEC strains.

<p>Detection of Stx in group beef samples spiked with STEC strains.</p

Detection of subtypes of Stx1 and Stx2 toxoids using the universal sandwich ELISA.

<p>A mixture of mAbs including mAbs Stx1-2, Stx2-5, Stx2b-1, Stx2e-2, and Stx2f-1 was used for capture (1 μg/mL each) and a mixture of Stx1 and Stx2 pAbs was used for detection (100 ng/mL each), the goat anti-rabbit IgG-HRP was used as a secondary antibody (10 ng/mL). The data shown represent the mean plus SD of three replicates from one representative experiment. Three individual experiments were performed.</p

Detection of Stx in culture supernatants of STEC strains by ELISA.

<p>Detection of Stx in culture supernatants of STEC strains by ELISA.</p