A New Method for Direct Detection of Heparin on Surface-Modified Intraocular Lenses

Background: Examination of surface-bound heparin on synthetic polymers can only be performed by few staining methods. These methods are limited by an only approximate detection of heparin visible at high magnification. Other methods only measure heparin quantitatively (per square dimension) and are rather sensitive to artifacts. Due to its homogeneous staining pattern, the modified toluidine blue staining technique, using a non-protein-based substance, allows examination and analysis of the homogeneity of the monomolecular heparin layer even under critical conditions like scanning electron microscopy. Materials and Methods: For critical examination of the heparin layer, this method was used…