TABLE 1.

Major differences between the competitive ELISA used in this study and Phipps’ ELISA

Type of ELISA	Type of plate	Coating	Coating time	Overcoating and fixing	Serum binding buffer	Serum dilution	Serum incubation time	Conjugate	Conjugate incubation time
Competitive	MaxiSorp (Nunc)	HSA-Hib	Overnight at 4°C	Yes	PBS–1% BSA–0.05% Tween 20	4-fold serial 1/50–1/3,200	3 h at 37°C	Alkaline phosphatase-conjugated goat IgG–anti-human Ig (IgG, IgM, and IgA) (Sigma), dilution 1/10,000	3 h at 37°C
Phipps’	PolySorp (Nunc)	HbHOA	90 min at 37°C	No	PBS–0.3% Tween 20–0.01 M EDTA	2-fold serial 1/20–1/5,120	1 h at room temp	Alkaline phosphatase-conjugated goat IgG–anti-human polyspecific Ig (Caltag), dilution 1/2,000	1 h at room temp