TABLE 2.

Effects of trypsin and different neuraminidases on the agglutination of rhesus erythrocytes by AAV4 and AAV5^a

Enzyme	Concn	Decrease in HA titer (fold change) for:
		AAV4	AAV5
Trypsin	0.2%	256	128
A. ureafaciens neuraminidaseb	100 mU/ml	>500	>1,000
	10 mU/ml	>500	>1,000
	1 mU/ml	250	32
C. perfringens neuraminidaseb	5 mU/ml	64	250
	1 mU/ml	2	16

^aRed cells were treated with neuraminidases isolated from different bacterial sources for 1 h at 37°C, washed, and tested in the HA assay in comparison with untreated red cells. A change of greater than fourfold is considered a significant result. Values presented are fold changes in HA titer required for 50% agglutination of cells compared to HA titer with untreated red cells. 

^bObtained from Roche Boehringer Mannheim.