The sweater box laminar flow hood really works using a hepa furnace filter. I made one about thirty years ago when a friend sent me some orchid pods. The first time I did everything perfectly except I forgot to add the sugar and ended up with a whole lot of tiny green dots. Even back then they no longer used flasks, but jars or tupperware with saran wrap, which is sterile as unwrapped. The way I did it, you cut a hole in the bottom of a plastic storage bin and buy a somewhat larger hepa furnace filter and fasten it over the hole from the back and add a fan. The flow rate should be very slow so as not to generate turbulence and the filter should be mounted on the outside so there is no bypass of unfiltered air around the filter if you mounted it on the inside. On Wed, Jan 7, 2026 at 10:39 PM Robert Lauf via pbs <pbs@lists.pacificbulbsociety.net> wrote: > > I used to get pre-made sterilized test tubes of medium from Phyto Tech but it looks like they aren't making them anymore. Too bad, because that eliminated screwing around with a pressure cooker. > You can buy a cute HEPA filter kit that can be mounted on a plastic storage bin and create a makeshift laminar flow hood. Haven't put that together yet but the next time I need to do embryo rescue I'll get it all set up and report how well it works. > Bob Zone 7 > > > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > https://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> > PBS Forum https://… _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net https://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> PBS Forum https://…