which is better and effective for fixation 4% paraformaldehyde or 10% neutral buffered formalin, please share your valuable comments
I think it depends on what you are fixing. In my lab we routinely do 10% NBF for tissues from rodents and 4%PFA for cell fixation for immunocytochemistry. Not sure exactly why though. I am interested in what other people think.
For wax 10 % NBF is fine.
If you want to control the antigen content of the tissue (for tricky antibodies) it is best to perfuse with freshly made PFA (ranging from 1-4%). It is important to never let the PFA heat to more than 50oC as I have read that it can form formic acid. You can control both the concentration of fix and amount of time in fixative.
There is another consideration: some of the best polyclonal AB are made by fixing with PFA or glutaradehyde before immunizing the animal. If an AB has been made with Glut fixation, it is best to use glut. If it has been made with PFA use that. Each of the fixatives changes the antigenisity of the tissues in specific ways. If you get an ab from a collaborator they will be able to tell you which fix they use. Most companies don’ give out how the ab was made.
I agree that it depends on what you want to fix but I use NBF both for immuno fixing and for fixing cells for plaque assays.