The SuperHT PAP Pen draws a water repellent circle around slide mounted tissue and prevents waste of valuable reagents by keeping the liquid pooled in a single droplet. The regular size pen has a 4 mm tip and can be used for about 800 applications. We also offer the Mini SuperHT PAP Pen, which has a finer 2.5 mm tip, and can be used for about 400 applications.SuperHT Pap Pen barriers are insoluble in aqueous buffers, detergents, alcohol and acetone, but can be removed with xylene. Barriers are stable at temperatures up to 120¿C.