TABLE 1.

Analysis of Stx binding in blood

Treatment (trial)	Fractiona	Amt of Stx (ng/ml)	Stx binding (ng of Stx/cell)
			Before washb	After washc
Stx2 (1)	Plasma	523
	PBMC	317	1.0 × 10−4	2.5 × 10−6
	Neutrophil	39	1.8 × 10−5	BDLd
	RBC	13	Not determined	Not determined
Stx2 (2)	Plasma	643
	PBMC	310	1.2 × 10−4	9.8 × 10−7
	Neutrophil	127	4.7 × 10−5	BDL
	RBC	7	Not determined	Not determined
Stx1 (1)	Plasma	1,022
	PBMC	589	4.0 × 10−4	BDL
	Neutrophil	168	5.3 × 10−5	BDL
	RBC	51	Not determined	Not determined

^aApproximately 5 μg of Stx1 or Stx2 was added to 3.5 ml of blood, incubated at 37°C for 1 h, and fractionated over Mono-Poly resolving medium.

^bThe numbers of cells in PBMC and neutrophil fractions were determined by flow cytometry and used to calculate the ng of Stx per cell.

^cCells were washed once in PBS prior to ELISA.

^dBDL, below the detection limit.