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pre-made holes for tissue are provided for the use of manual
method of making TMA (see subheading below) (Fig. 1a).
Otherwise, we need to make the “recipient” paraffin block
ourselves.- The wax is firm at room temperature but melts at temperatures
up to about 60 or 65 °C. The traditional advice with paraffin
wax is to use this at about 2 °C above its melting point. This is
to decrease viscosity and to create smooth wax blocks, the wax
in a big container first needs to be melted. Heat the paraffin to
60–70 °C for an hour to melt it. - Collect the melted wax into a metal mold. Choose a metal
mold that best corresponds to the size of “recipient” block.
Based on our experience, molds of 5–10 mm thick for generat-
ing the “recipient” blocks will provide a better quality result.
That is important to make sure that the block surface is hori-
zontal and equal to the base of the plastic cassette.
Fig. 1 Manual TMA. (a) Example of a pre-made “recipient” block with holes. A needle (gold color) is used to
punch holes in the “donor” blocks and transfer the tissues into the holes of the “recipient” block. (b) Punching
of the “donor” block by the needle. (c) Pull out the inner needle so that tissue is sucked into the empty cylinder
of the needle. (d) Transfer the tissue into the “recipient” block
Nassim Saremi and Alfred K. Lam