Elastic Fiber Staining of Slide Sections: A Technique to Observe Gastric Cancer Metastasis

First, use tissue paper to wipe off any excess solution on the slide or around the tissue. Place the slides in conditions that match room temperature and humidity. Add a few drops of potassium permanganate to each slide to oxidize them, making sure that the volume added is enough to cover the tissue section on each slide. After 5 minutes, rinse the oxidized slides with distilled water in Coplin jars, repeating the rinse two to three times, and using a new jar of water for each rinse. The tissue should have an observable brown color.

Now, add a few drops of oxalic acid to each slide to bleach them, making sure that the volume added is enough to cover the tissue section on each slide. After 5 minutes, rinse the bleach slides with distilled water, repeating the rinse two to three times, and using a new jar of water for each rinse. Wash the slides briefly in 95% alcohol.

Immerse the washed slides in elastin solution for 8 to 24 hours. Then, immerse the slides directly in 95% ethanol for 1 to 2 minutes to differentiate each tissue section well. Rinse the slides completely with distilled water.

Check microscopically for the blue-black elastic fibers staining and the gray background. It's better to slightly under differentiate the tissue since the subsequent Van Gieson's counterstain can also somewhat extract the elastic stain.

Counterstain the slides in a Van Gieson solution for 1 minute, making sure that the volume used is enough to cover the tissue section on each slide completely. Next, rapidly drop 95% ethanol onto the tissue slices for a few seconds to differentiate each tissue section well.