RE:pH paper vs. meter

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 Also, pH strips are quicker  because they require less ionic strength for
measurment.   EM Science/BDH has pH strips available with narrower ranges than
1.0 intervals.

We get calls occassionally when pH strips are not working. There are a few
influences that can cause errors.  I have an information sheet on the sources of
error in colormetric pH measurements that is not yet in our internet site.  If
you would like a copy, please let me know and send your fax number.

Rande Kline. HT (ASCP)
Technical Services
EM Science/BDH

Tamara Howard <> on 04/05/2000 05:27:15 PM

To:, Histology listserver <>
cc:    (bcc: Rande Kline/EMI/Merck)
Subject:  RE:pH paper vs. meter

>Lori Steele from Biogenex just gave a lecture at our State meeting.  She
>said that a pH meter is not necessary to check the buffer solution for
>immunohistochemical staining - just use a pH tape with 1.0 intervals.
>However, it still needs to be done each day you do IHC staining.  I know
>in our busy lab, it sure is quicker than having to use the meter.

>Becky Scholes
>Iowa Pathology Associates
>Des Moines, Iowa

Sorry, but this is not a good idea. Try for yourself - round up some pH
papers - different ranges and vendors - and try all on one buffer. My bet
would be that you'll get readings all over the place. Quicker may be nice,
but reproducibility is really worth the extra time - and it takes less
than 5 mintues to properly calibrate a meter and check your buffer's pH.

Tamara Howard

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