Technical Tips for Flaskers

Sterilizing disinfection tubes

Between flasking runs, autoclave your seed disinfection tubes and  stoppers. This serves two purposes: the first is that it destroys any  seed that may have remained behind, greatly reducing the chances of cross-contaminating your flasks with different seed. The second is that it reduces the  chance of bacterial or fungal contamination by destroying stray spores, etc.

Cleaning Glassware

The use of calcium hypochlorite often causes glass to be stained with  white calcium depostis. The best way to remove these is to soak the  glassware in dilute vinegar solution, or to use "CLR"  commercial cleaner to remove it. Using either of these acidic solutions will quickly remove any white buildup, allowing you to  clean glassware quickly and efficiently.

Aluminum Foil

Aluminum foil is your friend. Use it to wrap tools for autoclaving,  use it to cover the lids of your flasks, use it for sterile  workspaces. Replate forks can be wrapped in aluminum foil individually, and then wrapped in large numbers to form a single "burrito" of replate forks. Razor blades, for opening green  capsules, can be wrapped in foil for autoclaving. Tubes of water can  be capped with foil and held upright in the autoclave with balls of foil so they can be used for the sterile wash of seeds. Wads of  sterile aluminum foil, left over from other functions during flasking, can be used to support funnels for filtration techniques for washing seeds. A large square of aluminum foil can be wrapped up  or rolled, autoclaved, and then put into the flasking workspace to be unfolded. This sheet of foil can be used for many things, including  holding a large number of seedlings from a mother flask so they can  be put into replate flasks. The foil provides a large, clean, sterile  workspace for while you proceed with your work. Best of all, aluminum foil is recyclable; simply ball it up and throw it in the bin for  recycling when you're done.

Surface Disinfection

In order to disinfect your working surfaces, you may use either  chlorine solutions, or alcohol. I prefer not to use alcohol, due to  the fumes, expense, and flammability. It is much easier to make a disinfection solution in the following manner using chlorine bleach.

Using a measuring cup, take 2 parts (by volume) of 5.25% sodium  hypochlorite bleach. Add to this 24 parts of distilled water. Mix thoroughly. Add to this 2 parts of household vinegar (5% acetic acid). Do NOT add the vinegar until the bleach has been diluted by the addition of the water! This solution is then added to a spray  bottle. The solution is applied liberally to all surfaces that  require disinfection; use of hand towels (inexpensive white dish  towels from a discount store are perfect) to mop up the excess and wipe down surfaces is recommended.

When finished with the solution, unscrew the spray head, and pump  clean water through the sprayer. There is no reason to clean the reservoir; as long as the bottle is tightly sealed and refrigerated while not in use, the solution remains stable for at least two months. However, the solution will corrode the working parts of the sprayer if left inside the pump, so flush it by pumping plenty of  water through it.

Labeling

Labeling flasks can be a problem. There are several markers that write on glass and metal ("Sharpie" markers in particular); some fade with time. Be careful to make sure the writing is still  legible after applying disinfectants, or writing on surfaces that aren't clean.

Recently, we have started using black "Painters" markers, made by Hunt Manufacturing Company. The label reads "Painters Opaque Paint Marker," and it's the type with a shaker ball in it for mixing. Although long-term tests have yet to be completed, they seem like they resist disinfection, washing, and wear with good results. Art supply stores and hobby stores should have these.