TABLE 3.

Recovery yields of poliovirus from freshwater and seawater using various concentration methods

Membrane	Sample type	Acid rinse	Elution medium	Virus input		Virus recovered		% Recovery
				Concn (PFU/ml)	Vol (ml)	Concn (PFU/ml)	Vol (ml)
HA	Pure water with cationa	Applied	NaOHb	710	40	5,400	5	95
		Not applied	NaOH	710	40	1,900	5	33
		Applied	BEc	710	40	4,700	5	83
		Not applied	BE	710	40	4,500	5	79
1MDS	Pure water with cationa	Applied	NaOH	300	1,000	480	5	0.8
1MDS	Pure water	Applied	NaOH	350	1,000	394	5	0.6
		Not applied	NaOH	350	1,000	43,200	5	62
		Not applied	BE	710	40	2,850	5	50
HA	Sea water	Applied	NaOH	570	50	5,400	5	95
		Not applied	NaOH	570	50	1,950	5	34
		Applied	BE	570	50	5,350	5	94
		Not applied	BE	570	50	2,400	5	42
		Applied	NaOH	770	50	6,300	5	82
		Not applied	NaOH	770	50	3,200	5	42
1MDS	Seawater	Not applied	BE	770	50	460	5	6

^aMgCl₂ was added to pure water to obtain a final concentration of 25 mM Mg²⁺.

^b10 mM NaOH, pH 10.5 to 10.8, was used for elution.

^cBeef extract (BE) solution, pH 9.5, was used for elution.