I need help:
in the following sentence, which is right: "neither... nor", or "either... or" after a "no" is already in the sentence...?

"no effect of temperature could be seen (n)either in lipids (n)or in proteins"

I would go with (either - or) pair.
You need either ... or because you already have the negative word 'no':

No effect could be seen in either the ... or the ...

To express the same idea without the word 'no', you could say this:

An effect could be seen in neither the ... nor the ...