1 Used other than as an idiom: see outer ,â core. ( 2 planetology) The hot liquid material found near the centre of some planets, distinct from the solid inner core. ( 3 geology) The part of the Earth between the mantle and inner core, responsible for generating the planet's magnetic field. 4  Link/Cite.
Differential Staining is a staining process which uses more than one chemical stain. Using multiple stains can better differentiate between different microorganisms or structures/cellular components of a single organism.
Crystal violet - stains cell walls purple when combined with a mordant. This stain is used in Gram staining. DAPI - a fluorescent nuclear stain that is excited by ultraviolet light, showing blue fluorescence when bound to DNA. DAPI can be used in living of fixed cells.