I think the field of histology has more protocols than any other especially overlapping protocols. The histology field has been around for approximately 170 years. In that time thousands if not more people have re-defined every stain protocol to their liking. I have no doubt that every hospital in the world, that has a histology lab, has a different version of histology staining protocols. I know this because I worked at a private lab, then at Children’s Hospital Boston, then an academic lab (WPI), then my own lab (Histologistics). Each lab I worked at had a different protocol for the Masson’s Trichrome stain (and many others).
The reason(s) for the stain variations? A myriad of explanations, like personal preference, color differentiation, time constraints, chemical availability, company policy, etc. Most hospitals cut down on variability by buying pre-made stain kits. This reduces reagent solution variability made by different personnel. Hospitals also usually have pathologists who have defined preferences over stain colors, everyone like their version of the Trichome (Mallory’s, Masson’s, Gomori’s, and 14 published others).
Just because a stain protocol is working at a lab does not mean that same protocol will get the same results at a different lab. If the same stain kits are bought at the same time but used at different labs each person will do the stain a little bit differently. The type and quality of water used during staining can also have a big impact on the stain results. For us here in Massachusetts, we have very high iron deposits in the water which can make stains a little dull. When staining really counts, we have to use distilled (DH2O) water.
Here’s my versions of many stain protocols. There’s 45 free to download special stain protocols. Before you use them on any precious study slides, I suggest you try the stain on positive controls.
Note: All the pictures on the protocols and on this website were taken by me. If you see them on other websites, you know where they came from.