Immunohistochemical Analysis of von Willebrand Factor

For immunohistochemical analysis, the EnVision method was used according to Kloza et al. [55 (link)], using antibodies against von Willebrand factor (vWF) (1:2000, 2 h incubation at room temperature (RT), Polyclonal Rabbit Anti-Human (no cat. A 0082); DakoCytomation, Glostrup, Denmark). Antigen retrieval was performed before commencing immunohistochemical staining for vWF using Target Retrieval Solution (S1699; Dako, Glostrup, Denmark). A negative control was included, in which the antibody was replaced by normal rabbit serum (Vector Laboratories, Burlingame, CA, USA) at the respective dilution (no staining), and a positive control was included using rat lung stained for vWF. Immunohistochemical staining was evaluated on an Olympus BX41 microscope with an Olympus DP12 camera under 200× magnification.