Gibberelic acid storage

[Greg Allan]

I've just received a generous portion of GA3 from the CPS, and I've been wondering where the best place to store it may be. I don't want to use it all in one go. Also, is all GA3 the same strength? I ask because I've successfully germinated B. lamellata seeds in a tiny amount sent to me free by Byblis (Stefan), but there is much more in the container sent by the CPS.

Cheers

[Guest Aidan]

Strength depends upon dilution and different seeds require different dilutions.

[Greg Allan]

Hi Aidan. Excuse my ignorance, but I mean the actual strength of the powder before dilution. Is it always the same?

[Guest Aidan]

If the chemical is pure, yes.

[Guest Sheila]

If you store it in the freezer it doesn't degrade at all.

[byblis]

Hi Greg,

I have GAB3 from two different sources and every company tells different things:

Sigma-Aldrich: Store at room temperature

Second (Phywe if I remember correctly): Store at +4°Celsius

I keep it cool but not in the fridge and it still works. I think that you might loose it/some of it in the fridge if water condenses? and the GAB3 gets wet. it is said that GAB3 becomes inactive after 1-2 days diluted in water. That is the reason I donot like soaked paper GAB3.

Kindest regards

Stefan

[wobblepip]

I've stored the same batch of GA for years (about 10 years!) and it stills appears as effective now as it always was. It must be stored dry (organic compounds often degrade quickly in solution) and I store mine at room temperature (as stated in the 'data book') in the powder form. Try to obtain it from suppliers like Sigma as they tend to sell the purest forms. Unfortunately, they don't sell it to private households so you may have to find a friendly scientist to help you. A good concentration to use is 0.1% (w/v) and don't make up too much at once because it doesn't last long in the fridge. Also, make up the solution an hour or two before you need it as GA takes a little while to dissolve.

I find it excellent for breaking seed dormancy.

Paul.

[Dunc]

I've just received a generous portion of GA3 from the CPS, and I've been wondering where the best place to store it may be. I don't want to use it all in one go. Also, is all GA3 the same strength?

As noted by Paul, the pure form will keep almost indefinatly if kept in a dry sealed container and out of the light. I keep mine in the fridge in small clear lab bottles - FULLY LABELLED! As a solution it may keep in the fridge for a few weeks, as a solid it is not that important (the safety sheet says to keep it below 40 C....), just don't leave it in the sun on a hot windowsil and then expect it to work.

Its available in a number of 'forms', the normal ones you can easily buy are as a nearly pure powder (about 90% active) and as buffered 'tablets' (10 to 30 %). The pure stuff will not dissolve in just water - a drop of vodka is the easy solution (for the powder, not you). The tablets are designed to dissolve in water. You'll need to adjust amounts based on the quoted purity to get the desired 'active' GA3 in ppm (from 5 ppm for spraying plants, never tried on CPs, to a few hundred ppm for seeds). I've used both pure and tablet and found no difference - I've a bottle of finely ground up tablets that I can use to make small amounts of solution very easlily using mg's at a time and tend to use that.

8)