KOH

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mushroom mike
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KOH

Post by mushroom mike » Thu Mar 10, 2016 7:21 pm

Hello, I have just tried for a reaction on Stereum hirsutum with KOH. Pretty sure it's Stereum hirsutum and expecting red (or at first red, then black) on all surfaces. I had no reaction at all and am now wondering if my KOH has lost it's strength. On average how long would you expect it to hold it's potency?
Thanks in advance,
Michael.

Flaxton
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Re: KOH

Post by Flaxton » Thu Mar 10, 2016 7:42 pm

Hi Michael
I have just used some KOH which I have had for at least three years to test for red reaction on a young Fomes and it still worked for that. I didn't know and have been unable to find any details of the reaction for Stereum hirsutum, where did you get that info?
Mal

mushroom mike
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Re: KOH

Post by mushroom mike » Thu Mar 10, 2016 9:38 pm

Hi Mal, got the info from "Mushroom Expert. Com. I will try my KOH on another mushroom to see if I get a raction.Mine is less than 3 years old.
Mike.

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Chris Yeates
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Re: KOH

Post by Chris Yeates » Thu Mar 10, 2016 11:31 pm

Does one really need KOH to determine Stereum hirsutum? :o
I remember, over 30 years ago a course for Yorkshire mycologist beginners (I was definitely that back then) which Prof. Roy Watling and Malcolm Storey kindly ran. Roy said, at one point (talking about stains and reagents) "The gills of Amanita phalloides, stain lilac or pink with concentrated sulphuric acid; if you need to do that to recognise death cap . . . the door is over there". ;)
Chris
"You must know it's right, the spore is on the wind tonight"
Steely Dan - "Rose Darling"

mushroom mike
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Re: KOH

Post by mushroom mike » Fri Mar 11, 2016 8:21 am

Fair point Chris, I lack a bit of confidence and am just getting to grips with using stains and reagents. Strange that there was no reaction though!
Mike.

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Chris Yeates
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Re: KOH

Post by Chris Yeates » Fri Mar 11, 2016 10:50 am

mushroom mike wrote:Fair point Chris, I lack a bit of confidence and am just getting to grips with using stains and reagents. . . . .
Mike.
My comment was certainly not a criticism of you. KOH can be very important in, for example, the complicated world of Mollisia. Some species show a strong yellow reaction (often best seen under the microscope). One of the classics is Mollisia rosae: this is a nice, relatively easy, species to name with its occurrence on Rosa spp., hairy apothecia and this colour reaction - you can almost hear the 'pop' as KOH, added to a water mount, reaches the paraphyses:
http://www.ascofrance.com/uploads/recol ... a-0001.jpg
Cheers
Chris

PS - see also http://www.ascofrance.com/search_forum/3179
"You must know it's right, the spore is on the wind tonight"
Steely Dan - "Rose Darling"

mushroom mike
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Re: KOH

Post by mushroom mike » Fri Mar 11, 2016 12:22 pm

Thank you for the links Chris, looking forward to seeing a reaction on Mollisia rosae.
All the best,
Mike. :mrgreen:

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