title: A fluorescent probe assay (Heparin Red) for direct detection of heparins in human plasma.
abstract: Heparins are widely used anticoagulant drugs. The current monitoring practice for heparin in plasma, such as the chromogenic anti-factor Xa assay, relies on heparin-triggered activation of antithrombin, an inhibitor of coagulation proteases. Such assays are not applicable to the detection of non-anticoagulant heparins, an emerging class of drug candidates for therapeutic applications unrelated to anticlotting activity. This study describes the application of a commercially available fluorescent probe assay (Heparin Red) for the direct and sensitive detection of the "chemical" heparin in plasma, independent of any anticoagulant activity. The quantification range is about 0-5 μg/mL for both unfractionated heparin (corresponding to 0-1 IU/mL) and the low molecular weight heparin enoxaparin. The Heparin Red assay is of particular value for the quantification of non-anticoagulant heparins, as exemplified by the low molecular weight heparin derivative tafoxiparin and a N-desulfated-N-reacetylated heparin. Heparin octa- and decasaccharides are also detected. Graphical abstract Heparin quantification in plasma by mixing the sample with the Heparin Red reagent and fluorescence readout.
authors.affiliation: Inorganic Chemistry Institute, Heidelberg University, Im Neuenheimer Feld 270, 60129, Heidelberg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Warttinger
authors.affiliation: Inorganic Chemistry Institute, Heidelberg University, Im Neuenheimer Feld 270, 60129, Heidelberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Giese
authors.affiliation: Medical Faculty Mannheim, Heidelberg University, Maybachstr. 14, 68169, Mannheim, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Harenberg
authors.affiliation: Dilafor AB, Karolinska Institutet Science Park, Fogdevreten 2A, SE-171 65, Solna, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Holmer
authors.affiliation: Inorganic Chemistry Institute, Heidelberg University, Im Neuenheimer Feld 270, 60129, Heidelberg, Germany. kraemer@aci.uni-heidelberg.de.
authors.forename: Roland
authors.initials: R
authors.lastname: Krämer
mesh_terms: D015949:Factor IXa / Q000037:antagonists & inhibitors*; D005456:Fluorescent Dyes / Q000737:chemistry*; D005470:Fluorometry / Q000379:methods*; D064368:Healthy Volunteers; D006493:Heparin / Q000031:analogs & derivatives* / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques
chemical_list: D005456:Fluorescent Dyes; D006493:Heparin; D015949:Factor IXa
keywords: Assay; Fluorescent; Heparin Red; Non-anticoagulant heparins; Plasma; Tafoxiparin