TABLE 1.

NanH purification from recombinant E. coli

Purification step	Total activity (U)a	Sp actb	Purification factorc	% Recoveryd
Whole-cell lysate	1,734	0.002	1	100
Detergent extract	1,436	0.005	2.5	83
Ammonium sulfate precipitate	816	0.012	6.0	47
CM Sepharose	363	0.248	124	21
p-Aminophenyl oxamate	267	0.637	319	15
Sephacryl 200HR	141	1.614	807	8
DEAE Sepharose	101	1.900	950	6

^aOne unit of activity is defined as the amount of sialidase that releases 1 μmol of sialic acid per min. 

^bUnits of sialidase activity per microgram of protein. 

^cCalculated by dividing the specific activity of each preparation by the specific activity of the whole-cell lysate. 

^dDetermined by the following formula: (total units of activity of each preparation)/(total units of the whole cell lysate) × 100.