Electron Microscopy tissue sampling
Electron microscopy is sensitive to tissue handling procedures.
Whilst we recognise and appreciate that non-CMFT service users may
prefer to determine their own laboratory procedures pertaining to
the fixation and handling of the tissue samples that send to us for
examination, we ask all service users to appreciate that fixation
and handling procedures affording perfectly satisfactory light
microscopy fixation, may not necessarily remain suitable for
We therefore recommend that, in order to ensure the quality and
reliability of ultrastructural examination is not compromised, all
service users endeavour to meet the following conditions for all
tissue samples to be processed for EM:
a) Samples are placed into fixative (10% Formalin or 2.5%
buffered glutaraldehyde) immediately upon removal from the
NB. Buffered glutaraldehyde is preferred. Buffer should be 0.1M
phosphate buffer (pH 7.4).
b) If samples are fixed initially in Formalin, they are
transferred to 2.5% buffered glutaraldehyde at the earliest
opportunity and fixed at 4 - 20°C for between 24 - 72 hours, after
which time the sample must be transferred to 0.1M phosphate buffer
(pH 7.4) for transport (see section 4.3).
c) Samples fixed in buffered glutaraldehyde are not larger than
approx. 1mm3 in size.
(Last updated April 7th 2016)