Table 5. Quantitative autoradiography.

Brain tissue	Binding of 99m Tc-VHH	Competion binding
		Monomeric Aβ	Fibrillar Aβ
	ng (± sd)	ng (± sd)	ng (± sd)
APP/PS1	98.8 (±20,7)*	60.1 (±22.2)	31.4 (±14.3)
Wildtype	86.4 (±14.8)	56.4 (±19.5)	27.1 (±12.5)
AD human	190.1 (±73.5)*	81.4 (± N.D.)	42.3 (±29.2)
Control human	102.3 (±30.2)	27.2 (± N.D.)	49.9 (±17.4)

Differences in radioactivity were measured after application of 1 µg ^99mTc-pa2H to human and murine APP/PS1 brain sections.

^*Statistical difference (p<0.05) between either murine or human control versus Aβ bearing sections.