Dear Ummer, you can try to remove the Carnoy of the helminthes, wash in PBS and post-fixed in 1% osmium tetroxide by 2 h. There upon, the excess rinse in PBS again (or water), dehydrated in increasing acetone series starting at 30% acetone, 40%, 50%, 70%, 90% and 100%, dry in the critical point of CO 2, and after, to do the metallization. I have processed helminths fixed in 10% formaldehyde (preserved inside hosts in museum collections), or fixed in A.F.A. or Glutaraldehyde and I have obtained good information.

Thanks Jeannie Santos

Dear Ummer

samples fixed in AFA (92 parts ethanol 70%, 5 parts of formalin + 3 parts of acetic acid) and preserved in 70% alcohol can also be easily processed for SEM using the technique suggested by Dr. Jeannie Santos.

thanks Souza Lima