Table 3.

SPR analysis of samples containing protein material washed and eluted from empty and affine sorbents after lysate incubation.

Buffer Type	Volume, mL	Volume (on a Cumulative Basis), mL	Empty Sorbent (without PTGIS Immobilization)	Affine Sorbent (with PTGIS)
Wash buffer			Average binding levels (n = 2) with PTGIS on the chip, RU *
1X HBS-EP+	1	1.0	67	73
1X HBS-EP+	1	2.0	58	48
1X HBS-EP+	1	3.0	17	23
1X HBS-EP+	1	4.0	3	8
1X HBS-EP+	1	5.0	0	5
		Total	145	157
Elution buffer
0.25 M NaCl and 0.4% CHAPS	0.5	5.5	0	0
0.5 M NaCl and 0.4% CHAPS	0.5	6.0	0	7
0.75 M NaCl and 0.4% CHAPS	0.5	6.5	0	8
1.0 M NaCl and 0.4% CHAPS	0.5	7.0	1	13
1.5 M NaCl and 0.4% CHAPS	0.5	7.5	1	10
2.0 M NaCl and 0.4% CHAPS	0.5	8.0	8	26
		Total	10	54

* 1 RU (resonance unit) corresponds to 1 pg of protein bound to 1 mm² of the chip surface.