When an exact embedding of abelian categories induces a full embedding of their derived categories? Let $F:A\to A'$ be a (full) exact embedding of abelian categories. When $D(F):D(A)\to D(A')$ (or its bounded version) is a full embedding also? 
I would be interested in any necessary or sufficient conditions, and also in references! 
 A: It suffices to require that through any epimorphism in $A'$ from an object of $A'$ onto an object of $A$ some epimorphism in $A$ (onto the same object) would factorize; or the dual condition for monomorphisms.  The natural generality is that of exact categories (or perhaps even wider, but at least so).
The standard reference is Keller "Derived categories and their uses", Section 12.  Some additional details are recorded in my preprint "Contraherent cosheaves", http://arxiv.org/abs/1209.2995v3 , Proposition A.2.1 (no originality claim presumed).
A: My article on Embeddings of derived categories of bornological modules, arxiv math.FA/0410596, discusses your question for categories of bornological modules over bornological algebras (that is, with some functional analysis also envolved).  This notion has been reinvented several times by different people in different generality.  A somewhat older reference in a purely algebraic case is
Geigle and Lenzing, Perpendicular categories with applications to representations and sheaves, J. Algebra 144 (1991), 273-343.
A: If the left (or right) adjoint functor $A' \to A$ is also exact. This is sufficient, but not necessary.
