title: Factor VIII determination in patient's plasma and concentrates: a novel test equally suited for both matrices.
abstract: A novel assay for the determination of factor VIII (FVIII) is described. The assay uses a fluorescence-based detection system comparable with the common chromogenic test. At the same time, the assay is analogous to the clotting test as it does not involve pre-activation of FVIII. The assay was adjusted to perform equally well with patient's plasma and FVIII concentrates as samples. The combined employment of two different FVIII-deficient plasmas turned out to be of crucial importance in order to render the matrices as similar as possible to patient's plasma and, simultaneously, to obtain maximum sensitivity. Samples with a FVIII content down to 0.01 IU/ml are readily measured as are samples with a FVIII content of 1 IU/ml or somewhere in between. Upon dilution of samples, concentrates and plasma exhibited the same dose-response characteristics.
authors.affiliation: Paul Ehrlich Institut, Langen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Eich
authors.forename: Manuela
authors.initials: M
authors.lastname: Kusch
authors.forename: Claudia
authors.initials: C
authors.lastname: Grundmann
authors.forename: Christine
authors.initials: C
authors.lastname: Hanker
authors.forename: Rainer
authors.initials: R
authors.lastname: Seitz
authors.forename: Herbert
authors.initials: H
authors.lastname: König
mesh_terms: D002138:Calibration; D003374:Coumarins / Q000737:chemistry; D005169:Factor VIII / Q000032:analysis*; D005453:Fluorescence; D006405:Hematology / Q000379:methods*; D006467:Hemophilia A / Q000097:blood; D006801:Humans; D007201:Indicator Dilution Techniques / Q000592:standards; D009842:Oligopeptides / Q000737:chemistry; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D003374:Coumarins; D009842:Oligopeptides; C112975:tert-butoxycarbonyl-isoleucyl-glutamyl-glycyl-arginyl-amidomethylcoumarin; D005169:Factor VIII