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.
Bacteria that stain purple with the Gram staining procedure are termed Gram-positive; those that stain pink are said to be Gram-negative. The terms positive and negative have nothing to do with electrical charge, but simply designate two distinct morphological groups of bacteria.