Glow Writer Marking Pen for Autography Glow Writer™ is a fine-point phosphorescent ink marking pen for making experimental notations and other markings on chemiluminescent and radioisotope-labeled substrate materials (e.g., transfer membranes, dried gels, genomic and proteomic matrices, etc.) being analyzed by X-ray film autography or electronic imaging. The unique marker delivers a phosphor-containing ink through a fine point porous nib. Before exposure to X-ray film, the phosphorescent writing is excited by room light. A phosphor ink having an optimum concentration of phosphor and a relatively short afterglow halflife
(approximately 2-3 minutes) has been selected so that upon exposure to X-ray film, autographic exposures of almost any duration will be easily readable on the film. The fine point nib is easily replaceable if it dries out.