Although the researchers took the utmost care in handling the fragile slices, inevitable warps and tears occur when brain tissue is stained and cut, says co-author Alan Evans, a neuroimaging expert at McGill University in Montreal, Canada.
Ultrathin sections of the brain tissues were stained with lead citrate and uranyl acetate and examined with an LEO 912 electron microscope (JFE Enterprises, University of Maryland, College Park, MD).
These results suggest that well-mineralized bone is a serious obstacle to the diffusion of triiodide (herein, I3−) which may explain why the brain tissues were stained in both the neonatal and embryonic specimens [ 9, 15] but not here in this adult specimen.
In this study, samples from brain, skin, bone and heart tissue were stained with hematoxylin and eosin (H&E) for histopathological analysis (Fig. 1).
In the cases of the low-grade tumors where no normal brain tissue was resected, the tumor tissue was stained with non-targeted, streptavidin- PEG -QDs and goat-anti-moustreptavidin- PEG -QDs control.
Only stromal tissue is stained.
Both tumor tissue and normal brain tissue were also stained with control QDs lacking the EGF or primary antibody conjugation or conjugated to non-expressed epitopes and showed no binding.
Selected slides of brain tissue were also stained with a polyclonal antibody for identification of astrocytes (anti glial fibrillary acidic protein [GFAP], Dako, Glostrup, Denmark).
For immunohistochemical analysis, 3-µm thick sections of paraffin-embedded brain tissue were cut and stained with an antibody to Acanthamoeba spp. (from rabbits immunized with Acanthamoeba genotype T4) at a dilution of 1:2,000.
All brain tissue sections were stained by an automated immunostainer (Optimax Plus, BioGenex, San Ramon, CA) for uniformity.
