Nunclon™Δ cell culture flasks with surface areas from 25 to 175cm² are available with filter caps or Screw caps (Vent/Close caps) for good gas exchange. Short, wide neck allows easy access to entire growth surface. The Nunclon™Δ treatment is limited to the intended growth area. Neck areas are not treated to prevent cell attachment and growth in undesired areas. Certified pyrogen-free and tested for both monolayer formation and cloning efficiency employing primary cells as well as repeating cell lines. Sterile. Material flasks: Polystyrene Material caps: HDPE