There is a drain port at the bottom of the culture bottle for sterile liquid preparation; it is used with a sterile Filling Bell. The bottom has a 1/2inch hose connector for sterile dispensing.
WHEATON 3908-20 Culture Flask, Suspension Culture, Without Lid, Shinetek Instruments Research Institute (CAT#-STEM-CC-3426-LGZ) WHEATON 3906-05 Culture Flask, Media Storage and Dispensing, with Bottom Drain, Shinetek Instruments Research Institute (CAT#-STEM-CC-3421-LGZ) WHEATON 3906-07 Culture Flask, Media Storage and Dispensing, with Bottom Drain, Shinetek Instruments Research Institute (CAT#-STEM-CC-3422-LGZ) WHEATON 3906-09 Culture Flask, Media Storage and Dispensing, with Bottom Drain, Shinetek Instruments Research Institute (CAT#-STEM-CC-3423-LGZ) WHEATON 3906-11 Culture Flask, Media Storage and Dispensing, with Bottom Drain, Shinetek Instruments Research Institute (CAT#-STEM-CC-3424-LGZ) WHEATON 3906-13 Culture Flask, Media Storage and Dispensing, with Bottom Drain, Shinetek Instruments Research Institute (CAT#-STEM-CC-3425-LGZ)