In the very first Silent Hill, a part of the game takes place inside a hospital. In the hospital director's office, a strange red liquid is spilled on the floor and you must collect it in an empty bottle in order to get the game's best ending (by using the liquid to save officer Cybil instead of having to fight her, which also saves you a very nasty boss fight. This is not the sole requirement for getting this ending, however).
As far as I can recall from my first play-through, I did not see any hints that I should collect this red liquid (it didn't even occur to me that this was an option). Are there any in-game, plot-consistent hints that I missed?
I do recall there is a side-quest which hints to the red substance's purpose, but it only takes place after visiting the hospital. Am I only supposed to be aware of the red liquid's purpose on a second play-through?