We work with cell cultures grown on insert all the time. We have found
that the type of plastic the membrane is made from dictates the best
embedding media. For example, Bio Clear membranes do not cut well in
plastics but do fine in paraffin and as frozens.

When we process a membrane with insert into paraffin, we simply place
the insert, with membrane attached, into our tissue basket and process.
To embed, we harden a layer of paraffin over the membrane and then cut
the membrane and paraffin from the insert. Next, using a sharp knife,
cut through the membrane/paraffin making a block which can then be
placed in a mold and embedded to give a paraffin block.

Kimberlie Burns
Cystic Fibrosis Center
UNC-Chapel Hill