title: Differential suppression of background mammalian lysosomal beta-galactosidase increases the detection sensitivity of LacZ-marked leukemic cells.
abstract: A method is described for the detection of Escherichia coli beta-galactosidase-expressing leukemic cells in ex vivo bone marrow samples. 4-Methylumbelliferyl-beta-D-galactopyranoside is used as a substrate in a kinetic assay. D-Galactose is used to suppress endogenous lysosomal beta-galactosidase activity, yielding a sixfold increase in sensitivity. With this assay, the detection limit is one leukemic cell per 10(4) normal bone marrow cells.
authors.affiliation: Institute of Hematology, Erasmus University Rotterdam, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Hendrikx
authors.forename: A C
authors.initials: AC
authors.lastname: Martens
authors.forename: J W
authors.initials: JW
authors.lastname: Visser
authors.forename: A
authors.initials: A
authors.lastname: Hagenbeek
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000201:enzymology; D005690:Galactose / Q000737:chemistry; D005697:Galactosides / Q000737:chemistry*; D005819:Genetic Markers; D006863:Hydrogen-Ion Concentration; D006923:Hymecromone / Q000031:analogs & derivatives* / Q000737:chemistry; D066298:In Vitro Techniques; D007700:Kinetics; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D008247:Lysosomes / Q000201:enzymology*; D051381:Rats; D011914:Rats, Inbred BN; D012680:Sensitivity and Specificity; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000032:analysis* / Q000037:antagonists & inhibitors
chemical_list: D005697:Galactosides; D005819:Genetic Markers; D006923:Hymecromone; C026845:4-methylumbelliferyl-galactopyranoside; D001616:beta-Galactosidase; D005690:Galactose