Whispering-gallery resonant laser emission is reported in CdSe-tagged polystyrene microcavities. A clear intensity threshold for laser emission is observed. Using a recently developed asymptotic expansion derived from Mie theory, we have theoretically identified the experimentally observed discrete resonant peaks and assigned them to different quantum states. In fluorescent carboxylate-modified ellipsoidal polystyrene microcavities, we have observed that whispering-gallery mode and directional laser emission can be excited simultaneously. To understand our experimental results, we extend the asymptotic expansion from spherical to ellipsoidal microcavities to explain the whispering-gallery mode behavior and develop a simple ray-optics model to interpret the directional emission. The obtained numerical data agree well with experimental observation.