Tissue culture and cryopreservation are important emerging techniques for the “ex situ conservation” (i.e., “off-site conservation”) of plants. Without consistent work to preserve endangered species and varieties outside of their natural habitats (which are often disappearing under the pressure of human development and climate destabilization), there is little hope for the larger part of our world’s plant diversity.

For the last 15 years, the Huntington Library, Art Museum, and Botanical Gardens has dedicated itself to working on such protocols. As Sean Lahmeyer (the Huntington’s collections and conservation manager) explains, “we have plants in our collection that are critically endangered or extinct in the wild.” In many cases, the natural habitat for these plants is really no longer a viable place for them to thrive.

“So we determined we’d make this collection an ‘ex situ’ conservation collection. We are focused on developing protocols  that others can implement, hopefully in the country where the plants are found.  We aren’t trying to put our plant back in the wild. Instead, our research focuses on backing up live tissue through either tissue culture or cryopreservation, for longer term germplasm storage. Doing more of that is where we’re headed, training international botanists. We can equip people who wouldn’t normally have that opportunity.”

But that’s easier said than done, Sean notes. “Protocols aren’t at all transferable—we have to figure each out. It doesn’t matter if two plants are related taxonomically, or if they are from the same country; they have these specialized habitats, soils, nutrient preferences, that they’ve been with for millions of years. … It’s really a puzzle, getting something new into tissue culture. You can spend years doing it.”

Tissue Culture Protocol Development: No Time for Wasting Time

The major bottleneck for the Huntington has always been qualified staff; anything that eats up their time makes their program less productive. For more than a decade their lab struggled with an autoclave that devoured time as surely as it devoured water and electricity. 

“The building was built in 2000, and at that time it went to a subcontractor, and they didn’t understand what we’d be using it for. So that got us a big autoclave, like you’d see in a hospital. … It was meant for daily usage in a hospital setting. It was overkill. Everything about it was expensive. And we kinda made it work … for about a decade, we kinda just kept it limping along.”

When that was no longer viable, they switched to a Priorclave autoclave for their tissue culturing work. 

“It seemed like a simply designed unit that worked and I started talking to end users in California, and they all liked it… the unit looks solid. If there’s a problem, it’s mechanical, that makes sense out of it, we can see the problem. It isn’t ethereal. … It’s not full of bells and whistles.”

Most importantly, the in-tank heater and fully programmable cycles meant much less waiting around for the autoclave to be ready. 

“We like the fact that it doesn’t take forever to warm up. We can all get what we need to done. The cycles aren’t that long and that really helps us. The other unit, we’d have to schedule more, because it took forever to warm up. … And when you warm it up, you constantly heard a drip.”