title: Errors arising from incorrect orientation of E test strips.
abstract: Major errors arise if E test strips are placed upside down. Asymmetric zones, or no zone at all, may result. MICs indicated by upside-down tests were almost always considerably higher than true values. This situation differs markedly from that for conventional testing, where orientation of disks is not important.
authors.affiliation: Department of Medical Microbiology, Royal Free Hospital School of Medicine, London, United Kingdom.
authors.forename: J M
authors.initials: JM
authors.lastname: Hamilton-Miller
authors.forename: S
authors.initials: S
authors.lastname: Shah
authors.forename: T S
authors.initials: TS
authors.lastname: Yam
mesh_terms: D001419:Bacteria / Q000187:drug effects; D003951:Diagnostic Errors; D004352:Drug Resistance, Microbial; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data