A method is described for the detection of Escherichia coli β-galactosidase-expressing leukemic cells in ex vivo bone marrow samples. 4-Methylumbelliferyl-β-D-galactopyranoside is used as a substrate in a kinetic assay. D-Galactose is used to suppress endogenous lysosomal β-galactosidase activity, yielding a sixfold increase in sensitivity. With this assay, the detection limit is one leukemic cell per 104 normal bone marrow cells.

doi.org/10.1006/abio.1994.1516, hdl.handle.net/1765/60012
Analytical Biochemistry
Department of Hematology

Hendrikx, J., Martens, A., Visser, J., & Hagenbeek, A. (1994). Differential suppression of background mammalian lysosomal β-galactosidase increases the detection sensitivity of LacZ-marked leukemic cells. Analytical Biochemistry, 222(2), 456–460. doi:10.1006/abio.1994.1516