Immunohistochemical Staining of Biomarkers in Brain Tumor Neurosphere Sections

Take a slide with paraffin-embedded sections of brain tumor neurospheres, clusters of neural stem cells exhibiting tumor-specific nuclear protein biomarkers.

Heat to melt paraffin, remove it using xylene, and rehydrate the tissue using decreasing alcohol concentrations.

Heat in an acidic buffer containing detergent to unmask epitopes on the biomarkers and permeabilize cellular membranes.

Rinse, then treat with an oxidizing agent to inactivate endogenous peroxidase enzymes, preventing non-specific signals.

Apply a blocking solution to mask non-specific binding sites.

Incubate with primary antibodies targeting the biomarker epitopes.

Rinse, then treat with biotin-conjugated secondary antibodies that bind to the primary antibodies.

Rinse and incubate with a peroxidase enzyme-conjugated avidin, which binds to biotin. 

Add a chromogenic substrate and an oxidizing agent.

Peroxidase utilizes the agent to convert the substrate into colored precipitates, labeling the biomarker location.

Counterstain the nuclei, dehydrate the tissue in alcohol, and mount the slide for imaging the biomarker distribution.