  We use superalgebras to realize the 3-algebras used to construct N=6, 8
Chern-Simons-matter (CSM) theories. We demonstrate that the superalgebra
realization of the 3-algebras provides a unified framework for classifying the
gauge groups of the N \geq 5 theories based on 3-algebras. Using this
realization, we rederive the ordinary Lie algebra construction of the general
N=6 CSM theory from its 3-algebra counterpart, and reproduce all known examples
as well. In particular, we explicitly construct the Nambu 3-bracket in terms of
a double graded commutator of PSU(2|2). The N = 8 theory of Bagger, Lambert and
Gustavsson (BLG) with SO(4) gauge group is constructed by using several
different ways. A quantization scheme for the 3-brackets is proposed by
promoting the double graded commutators as quantum mechanical double graded
commutators.
