FlytrapCare Carnivorous Plant Forums

Hi all,

I would like your feedback on how I am planning to prepare my Kinetin stock solution:

I got 1g of Kinetin in powder form (preferred powder due to importing).
First I am going to solve it with 2 ml of 1N KOH.
Now the most natural thing to do would be to mix that with 1 liter of distilled water to have a 1mg/ml concentration, like everyone else.

However, as I want to save space in the freezer, I am planning to just add 98ml of water to create a 10x (10mg/ml) Kinetin solution. If the fine dosing with 0.1ml instead of 1ml annoys me, I could take 10 ml of that concentrated solution and add 90ml distilled water in a 2nd 100ml (1mg/ml) bottle in the freezer.

Any objections, suggestions, or sounds right?

Thanks!

Hi Volker,

What if you dissolve by milligram? That way, you don't have to freeze the remaining solution. You can also proceed with your plan which sounds fine.

hb

I think the weighing scale I had to buy for that purpose would be as expensive than 100 liter of Kinetin...

1. I dont recommend to use distilled water to dissolve hormones, because it will deteriorate after contamination ( fungus, bacteria ) and some hormones does not dissolve well in water.1N KOH for example is better.
2.the stock solution concentration does depend upon how much media you will prepare at a time and the lowest concentration of hormone you want to use. For example i prepare regularly 250ml of media, because my pressure cooker is not able to hold more flasks.And the lowest concentration i need to use is 0.1mg/L of Kinetine. So i am using stock solution 0.25mg/ml of Kinetin and 1mL pippete which does have 0.1ml divisions.
Because i have cheap scales which measure only +-10mg i prepare the stock solution from 50mg of Kinetine dissolved in 200ml of 1N KOH.

Thanks for your answer!

Regarding 1. I mentioned above that I am using 1N KOH for solving the hormones and then add distilled water. So you are using pure 1N KOH without water at all? Isn't that killing the pH level of your media? Well - I guess not Is that common practice here?
I don't like the idea too much, though. As we store it in our normal food-freezer and there is always a minor chance that somebody might drop it on the floor. A bit dangerous with 1N KOH...

I got a huge pressure cooker, so I should be able to handle 1 liter and 35+ vessels and I am ok preparing that much at once. I will have to search harder for a pipette like yours, so I could skip the 1x solution at all. I think I could even live with a 0.5 mg/l Kintetin accuracy for now.

Hi,
Check this out for cheap scales, and these are the dear ones. I had my doubts before buying them but they are great.
I am sure they will be available in most countries.
http://cgi.ebay.com.au/Digital-Touch-sc ... 3a52b89475

Hi Geoff,

That's exactly the kind I am using. You can order them straight from the source in Hongkong (available through Ebay), at about USD10-15 shipped. I was able to find it locally in Manila, however only the 0.1/500 model (for USD 7 ), which I am using right now.
I thought it should be good enough, didn't expect myself to use 10x solutions, haha. But I think I can still manage.

Thanks,
Volker