A mixture of potassium chromate and 100% sulfuric acid is the traditional
way. Unfortunately, it's (at least in Germany) almost impossible to get rid
of the stuff. You may also try Hellmanex, a detergent sold by Hellma
especially for this purpose (some people claim it's even better than
the "traditional approach", and it's certainly more friendly to your
environment).
--Cornelius.
--
/* Cornelius Krasel, U Wuerzburg, Dept. of Pharmacology, Versbacher Str. 9 */
/* D-97078 Wuerzburg, Germany email: pha...@rzbox.uni-wuerzburg.de SP3 */
/* "Science is the game we play with God to find out what His rules are." */
I use Hellmanex II solution (from Helma) at 2% for at least
30 minutes, and usually overnight. For me it is enough to clean my
cuvettes in the 95% of the cases, taking into account that I always
have protein precipitation in my experiments. However, some proteins
still stick to the quartz and then I use 6M nitric acid overnight
or even "overweekend".
Good luck
Jesus
I keep my cuvettes all the time in a mild detergent. At the momoent I am
using Contrad 70 from Baxter.
For very hard to remove dirt, e.g., I 'inherited' some very dirty
specialty cuvettes, I put them into chromogenic-sufuric acid for a
night. You can buy small bottles with a chrome-salt solution you just
have to add to a normal bottle of sulfuric acid.
Achim
try soaking your cuvettes for a few hours in Aqua Regia (3:1 HCl:HNO3)
and then thoroughly rinsing your cuvette with ddH2O
joe.
> Hi, folks! Does anybody have any suggestions about a good way to clean
> proteins out of quartz cuvettes? I have used concentrated nitric acid in
> the past, and also 3M HCl/50% ethanol (which doesn't seem to work as
> well, at least in my experience). Is there anything else that works well
> (say, 50% nitric)?
>
>
In our lab, we fill the cuvette with 2% of RBS(from Pierce,
Inc.), soak it in an ultra sonic cleaner for 15-20 min. This method
works very well even in a very short pathlength cell (50 um).
Hope this helps.
C. Krittanai
Dept of Biochem and Biophysics
Oregon State University.
saek...@ucs.orst.edu
===================================================================
>Matthew Parker (par...@topaz.microbio.uab.edu) wrote:
>> Hi, folks! Does anybody have any suggestions about a good way to clean
>> proteins out of quartz cuvettes? I have used concentrated nitric acid in
>> the past, and also 3M HCl/50% ethanol (which doesn't seem to work as
>> well, at least in my experience). Is there anything else that works well
>> (say, 50% nitric)?
We just use the high UV transmission disposable methacrylate cuvettes
Pete
aren't these expensive ? quartz cuvettes are best cleaned with a warm (60C)
solution of 1% SDS, leave for 10 min or so, rinse with copious
amounts of H2O. Do not use concentrated H2SO4: even quartz is damaged
by this.
z
How often does your lab clean your cuvettes after each sample, set
of samples, periodically?
thanks, toddJ
Matt
if you clean cuvettes between runs..
we have in our lab a set-up which hooks on to your house vacuum line
and essentially it contains a reservoir to put cleaning solvent in
and then it vacuums the solvent into/out of the cuvettes (with the
cuvettes being upside down)
typically we clean the cuvettes with 95% ethanol thoroughly and then with
water.. the use of the vacuum, allows the cuvettes to come out dry as well
Joe Hilario In a sea of faces, in a sea of doubt
UIC Dept. of Chemistry In this cruel place your voice
jove...@uic.edu above the maelstrom
j...@hugh.chem.uic.edu --The Sisters of Mercy, "Marian"
jove...@icarus.cc.uic.edu
Especially when you are working with very hydrophobic substrates, or
enzymes very sensitive to changes in the surface tension. I worked for a
while with lipases. The washing of the cuvettes between the assays was
like a ritual, you forget one step and everything is messed up.
Achim
<snipped for brevity>
>>
>>We just use the high UV transmission disposable methacrylate cuvettes
>>
>>Pete
>aren't these expensive ? quartz cuvettes are best cleaned with a warm (60C)
>solution of 1% SDS, leave for 10 min or so, rinse with copious
>amounts of H2O. Do not use concentrated H2SO4: even quartz is damaged
>by this.
>z
I agree with your comments on cleaning, although we use 2% Decon.
But regarding cost of disposable cuvettes, I do not think that they
are excessively expensive. The 4.5 ml ones we use are made by Kartell,
and cost about 10GBP/25DM/16USD per hundred. So you can get about 600
disposables for the price of one quartz cuvette. The relative
economics are dictated by how ham fisted you/your colleagues are :)
Pete
I agree, if you want to do serious spectroscopy, esp. in the lower
wavelengths, you should use quartz cuvettes. For the range >400nm it
might not be that necessary.
Achim