With "PBS" do you mean phosphate buffer solution? At around pH 7? If so, then it's just for preservation. Even if you simply google it you'll easily find information that shows that is a good preservation technique.

Thanks Mário for your answer. I’m aware of that. My question is regarding the reconstitution of the product. Some people use saline, others use phosphate buffer saline… But I’ve not seen studies using water, as it is recommended by the manufacturer.

I believe it is related to the application. If you are using it to study neurological effects "in vivo" by injection, then the saline phosphate buffer mimics better the

cerebrospinal fluid.

Thanks :)