Sorry, that I wasn't able to reply earlier.
Combining the COX with the SDH can demonstrate COX negative fibres, which
may or may not be SDH positive and which may or may not be ragged red
fibres; (3 of the 13 subunits of COX are encoded by mitochondrial DNA
whereas SDH is encoded by nuclear DNA and therefore not affected by
mitochondrial DNA mutations). Ragged red fibres in mitochondraial myopathies
are generally COX neg (except in MELAS). Intra fibre mosaicism (mixture of
bluish COX deficient and brownish COX positive mitochondria within the same
fibre are also well demonstrated by this combined technique).
I hope this isn't too confusing?



----- Original Message -----
From: Neuropathology <Neuropath.Frenchay@dial.pipex.com>
To: <kathy.cash@imvs.sa.gov.au>
Sent: Thursday, 5 July 2001 06:13 am
Subject: Cytochrome/SDH


> Sorry I can't help with your problem as I have never done the combined
> method.  In fact I would like to know why do you combine the methods?  I
am
> always intrigued by the many and varied ways that we find to get a result.
>
> Andy Shand
> Neuropathology
> Frenchay Hosp.
> Bristol
>