  Usual separability criteria applicable to distinguishable particles are not
applicable to identical particles. Here we show that Partial transposition and
symmetrization (or anti symmetrization) of density matrix of bipartite boson
systems (fermion systems) can be used to check whether a state is separable or
not.By using determinant based separability criteria it has been found that
bipartite states of identical particles are always separable. It is found that
partial transposition and symmetrization is equivalent to realignment criteria
proposed by Wu.
