TABLE 2.

ELISA titers of adult sera before and after absorption^a

Absorbent	IgG titer to UspA1 in sample:						IgG titer to UspA2 in sample:
	1	2	3	4	5	6	1	2	3	4	5	6
Noneb	161,750	873,680	154,650	10,330	35,780	19,130	87,180	248,290	146,900	7,860	31,230	13,200
UspA1	2,450	2,210	3,160	1,650	<500	3,010	2,800	2,120	2,700	2,220	<500	<500
UspA2	42,620	90,150	33,570	6,420	3,490	4,130	<500	1,820	3,010	2,960	<500	<500
74-kDa protein	137,530	517,970	208,240	25,930	20,570	37,570	64,760	84,590	208,240	25,930	20,570	37,570

^aFor the absorption, an aliquot of adult serum was diluted and mixed with purified UspA1 or UspA2 from the O35E strain to a final 50-μg/ml protein concentration and a final 1:10 serum dilution. The mixtures were incubated at 4°C for 2 h, and precipitates were removed by microcentrifugation. The titers of IgG to the UspA1 and UspA2 proteins are endpoint titers starting at a serum dilution of 1:500. 

^bSaline was added to these samples in place of purified protein (at an equivalent volume), and samples were treated the same thereafter.