Table 2.
Bioassays of brain tissue and spiked hot dog-brain mixtures under various test conditions
| Subject | Test conditions
|
Log10 dilution of sample (weights of brain loaded onto gel)
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Pressure, MPa | Temperature, °C | Number of 1-min pulses | 1 (5 mg) | 2 (0.5 mg) | 3 (50 μg) | 4 (5 μg) | 5 (0.5 μg) | 6 (50 ng) | 7 (5 ng) | 8 (0.5 ng) | |
| Brain tissue | |||||||||||
| Ambient | Ambient | 0 | 4/4 | 4/4 | 4/4 | 4/4 | 4/4 | 0/4 | |||
| 1,200 | 135 | 3 | 4/4 | 3/3 | 5/5 | 2/4 | 0/3 | ||||
| Hot dogs | |||||||||||
| Ambient | Ambient | 0 | 4/4 | 4/4 | 6/6 | 7/7 | 4/4 | 3/4 | |||
| 1,200 | 135 | 3 | 3/4 | 0/4 | 1/4 | 0/3 | |||||
| 1,000 | 135 | 3 | 4/4 | 4/4 | 3/4 | 1/5 | |||||
| 690 | 124 | 3 | 3/3 | 4/4 | 4/4 | 4/4 | |||||
| 1,200 | 135 | 10 | 3/3 | 1/4 | 0/4 | 0/4 | |||||
| 1,000 | 137 | 10 | 2/4 | 1/4* | 1/4 | 1/4 | |||||
| 690 | 121 | 10 | 4/4 | 4/4 | 4/4 | 3/4 | |||||
| 1,200 | 142 | 1 (5 min) | 1/2 | 0/3 | 0/4 | 0/3 | |||||
| 0.2 | 121–134 | Autoclave (5 min) | 0/4 | 1/4 | 0/4 | 0/4 | 0/4 | 0/4 | |||
Fractions represent positive over total number of inoculated animals.
*
The positive animal was unique in having a subclinical infection (documented by the presence of cerebral PrPres) when killed at the conclusion of the study. All other PrPres-positive animals were symptomatic, and in no other asymptomatic animal was PrPres detected in the brain.