title: Does sampling site influence levels of free thyroxine and thyrotropin determined by a current immunoassay?
authors.affiliation: Isala Klinieken, Department of Clinical Chemistry, P.O. Box 10400, 8000 GK Zwolle, The Netherlands. j.rondeel@isala.nl
authors.forename: Jan M M
authors.initials: JM
authors.lastname: Rondeel
authors.forename: Jaldira S
authors.initials: JS
authors.lastname: Albers
authors.forename: Eelco J
authors.initials: EJ
authors.lastname: Schroor
authors.forename: Roger K
authors.initials: RK
authors.lastname: Schindhelm