[Histonet] Biomaterial embedding in paraffin - sections detach from the slides

[Marina Santos]

Hi,

 

I am having problems with sections sliding off from the slide even from the
slides with positive charges (treated for frozen sections). However, I am
not working with human tissue.  I culture cells in a scaffold material, that
is a biomaterial made from a blend of starch with polycaprolactone (30/70
wt%), and then I embed it in paraffin. The problem is that after
deparaffinization and during the washing steps the material detaches from
the slides. This also happens with frozen sections of this biomaterial,
therefore I am thinking that the problem is related with the chemistry
nature of my biomaterial. Besides being hydrophobic, the biomaterial also
has a neutral charge. With human tissue there isn't such big problem because
it is hydrophilic, i.e., the same polarity as the glass and besides that is
negatively charged so strong interaction will be established with the
positively charged glass slides. I already eliminated some of the most
common situations that could justify the detachment of sections from glass
slides:

 

1)       paraffin sections were very well dried

2)       I tried buffers for antigen retrieval with different pH (citrate
and EDTA). I even avoided the step of antigen retrieval but even so the
sections were detaching

3)       The biomaterial was fixed for long time but I also tried short time

4)       There were no wrinkles in the sections

 

Therefore, I am really convinced that the problem relies in the chemistry of
the biomaterial. Do you have any suggestion how to go around this problem?
Any glass slide with a treatment that might improve the adhesion of the
sections? Or any other suggestion that might not be related with material
chemistry?

 

Thank you in advance.

 

Marina Santos

 

Department of Polymer Engineering

University of Minho

Portugal