For the STS I will be using Tony Green’s notes he shared on here on OverGrow
PREPARATION OF SILVER THIOSULFATE (STS) SOLUTION
Sigma-Aldrich:
Silver Thiosulfate (STS) is commonly used to block the action of ethylene in plant cell cultures. Ethylene is a hormone that is present in the gaseous state. Ethylene increases during senescence and ripening, and has been shown to increase in plant cell cultures due to
wounding or the presence of auxins. Silver nitrate may be used alone to block the action of ethylene but it is not transported as well as STS thus is seldom used alone.
Prepare a 0.1 M Sodium Thiosulfate (STS) stock solution by dissolving 1.58 g of Sodium Thiosulfate anhydrous or 2.48 g sodium thiosulfate pentahydrate(x1.56) into 100 ml of water.
Prepare a 0.1 M Silver Nitrate stock solution by dissolving 1.7 g of Silver Nitrate into 100 ml of water. Store the stock solution in the dark until needed to prepare the STS.
The STS solution is prepared with a molar ratio between silver and thiosulfate of 1:4, respectively. Nearly all of the silver present in the solution is in the form of [Ag (S2O3)2]3-, the active complex for ethylene effect inhibition.
Prepare a 0.02 M STS by slowly pouring 20 ml of 0.1 M silver nitrate stock solution into 80 ml of 0.1 M sodium thiosulfate stock solution while stirring vigorously.The STS can be stored in the refrigerator for up to a month. However, preparation of the STS just prior to use.
Dilution strengths quick reference :
100 ml .02 M sts solution at:
20mM straight stock
15mM add 33 ml water
10mM add 100 ml water
6mM add 233 ml water
5mM add 300 ml water
4mM add 400 ml water
3mM: add 557 ml water
2mM add 900 ml water
1.5mM add 1230 ml water
1mM add 1900 ml water
.5 mM add 3900 ml water
.3mM add 6570 ml water
I did some math for adjusting the sigma recipe for no left overs: for 300 ml .02M sts the recipe is
1.0192 grams silver nitrate in 60 ml water
And
5.9566 grams sodium thiosulfate pentahydrate in 240 ml water
Or
3.7946 grams sodium thio anhydrous in 240 ml water
Seems cheap scale friendly. Penta friendly (most readily avail) and you dont have leftovers that you have to mix more to use.
