De-sialylation of PrP^C increases the rate of PrP^Sc amplification in PMCAb.

<p><b>A.</b> 263K, HY, Drowsy or SSLOW scrapie brain materials were diluted 10³–10¹⁰-fold into 10% NBH, dsNBH or mock treated NBH (NBH incubated with a buffer for enzymatic de-sialylation in the absence of sialidase) as indicated and subjected to a single PMCAb round. Undigested 10% NBH was used as reference. <b>B.</b> Analysis of PrP^Sc amplification fold. Scrapie brain materials were diluted 10⁴-fold for 263K or 10³-fold for SSLOW into 10% NBH or dsNBH as indicated and subjected to four serial PMCAb rounds. The material amplified in each round was diluted to a specified dilution fold into 10% NBH or dsNBH for the next PMCAb round as indicated. Unamplified seeds are shown as round 0. Prior to electrophoresis, samples were treated with PK. All blots were stained with 3F4 antibody.