Figure 8From: Collection of corneal impression cytology directly on a sterile glass slide for the detection of viral antigen: An inexpensive and simple technique for the diagnosis of HSV epithelial keratitis – A pilot study Detection of HSV-1 antigen. Impression cytology smear showing corneal epithelial cells from a patient with mycotic keratitis showing the absence of viral antigen. Note the absence of background staining. Indirect immunoperoxidase assay, × 500.Back to article page