All of the answers end in -INE:
ROMAINE
TURBINE
FETUCCINE
GRENADINE
CODEINE
DEFINE
IMAGINE
LABYRINTHINE
SKYLINE
JASMINE
STRYCHNINE (probably the toughest one)
HEROINE
PORCUPINE
WOLVERINE
COSINE
SERPENTINE
EQUINE
Take the shaded letters from the appropriate words to get the four bases of DNA: ADENINE, CYTOSINE, THYMINE, and GUANINE. These are standardly abbreviated to A, C, T, G.
Following the same -INE pattern, NINE WEST is a store on the 4th floor.
As a biologist and puzzle designer, I was thrilled that A, C, T, and G randomly ended up being the letters for one floor, and more excited still to find a Nine West on that floor.