Infectivity titers in scrapie-infected WT and anchorless PrP transgenic (tg44) mice.

aFollowing IC inoculation, tissues were analyzed at 482–654 days for tg 44 mice and 155–165 dpi for WT mice. Plasmas were analyzed from 365–596 dpi for tg44 and 155–165 dpi for WT mice.
bTiters are expressed as log10ID50/gram tissue or ml plasma [37]. When recipient mice were inoculated with 50 µl of a 1% tissue homogenate or 50 µl of a 1/100 plasma dilution, the lower limit of detection was 2.8 log10ID50/gram tissue or ml plasma. Some mice were inoculated with 50 µl of a 1/10 dilution of plasma, so the lower limit of detection was 1.8 log10ID50/ml plasma. Tissues from mock-inoculated or uninoculated mice had no detectable infectivity.
cTwo tg44 mice inoculated IP were sacrificed at 441 and 692 dpi.
dThese low or negative plasma titers differed from a previous report [25], where titers of >5.0 and >7.0 log10ID50/ml were found in two anchorless PrP tg mice at 480 and 507 days post-infection with the RML scrapie strain.
eMice inoculated with RML scrapie strain.
Mice without footnote were inoculated with 22L scrapie strain.