RE: automated IHC - Dab disposal

From:Philip Oshel <>

How about reducing the volume with a roto-vap to say, one liter, then 
running the potassium permanganate/sulfuric acid reaction on that? I 
wouldn't think the DAB is volatile enough to come off before the 
water, but am I wrong?


>Hi Hazel,
>thanks for your reply to my query. Just a 2 things that need clarification.
>Firstly, when you say "working DAB" is this the amount of DAB in the waste
>disposal container or the amount of liquid dab as used per run-excluding all
>the water used for washing out the machine at the end of a clean cycle ? i.e
>a run of 48 slides would use 200ul each = 9600ul, but then would be diluted
>by water for the "wash cycle?" am I getting you confused?
>Secondly, what volume are you dealing with each day? I get about 10l per
>week, and I am concerned that I will end up with huge carboys of pot permang
>and sulphuric acid and gently bubbling solutions lying all over the place!
>This is getting to be quite a problem!!!
>Best regards
>-----Original Message-----
>From: Horn, Hazel []
>Sent: 13 November 2000 09:07
>To: 'Louise Taylor'; histonet
>Subject: RE: automated IHC - Dab disposal
>>  Louise,
>>  This is the procedure approved by our state water department for disposal
>>  of used DAB waste from our Dako autostainer.   You might need to check
>>  with your state water department before using this procedure.
>	[Horn, Hazel]
>	1.   Prepare the following stock solutions:
>	      0.2 M Potassium Permanganate (31.6 g KMnO4/liter)
>	      2.0 M Sulfuric Acid (112 ml concentrated acid/liter)
>	2.  For each 10 ml of working DAB solution, add:
>	     5 ml 0.2 M Potassium Permanganate
>	     5 ml 2.0 M Sulfuric Acid
>	3.  Allow the mixture to stand for at least 10 hours.   This will
>allow it
>	     to become noncarcinogenic.
>	4.  To decolorize the mixture, add powdered ascorbic acid until the
>	     color disappears.
>	5.  Neutralize  the decolorized mixture with sodium bicarbonate.
>	     the neutrality (pH meter, pH paper or dipsticks)
>	6.  Discard by pouring down the drain with copious amounts of
>	    water.
>	If anyone has a simpler method we would sure love to have it.    By
>the way, our water department will not allow us to use the procedure using
>	bleach.
>	I hope this helps!!!
>	Hazel
>>  I asked this question last week, but due to technical errors received only
>>  one reply, so I'm asking it again. How do labs using the Dako autostainer
>>  deal with their DAB waste? Have it collected by a waste company? If so -
>>  what do they do with it?
>>  Deal with it in-house? Pour it down the drain?
>>  Best regards
>>  Louise Renton
>>  Research Laboratory
>>  Department of Anatomical Pathology
>>  South African Institute for Medical Research
>>  Johannesburg
>>  South Africa

Philip Oshel
Supervisor, AMFSC and BBPIC microscopy facilities
Department of Animal Sciences
University of Wisconsin
1675 Observatory Drive
Madison,  WI  53706 - 1284
voice: (608) 263-4162
fax: (608) 262-5157 (dept. fax)

<< Previous Message | Next Message >>