  We define an invariant of transverse links in the standard contact 3-sphere
as a distinguished element of the Khovanov homology of the link. The quantum
grading of this invariant is the self-linking number of the link. For knots,
this gives a bound on the self-linking number in terms of Rasmussen's invariant
s(K). We prove that our invariant vanishes for transverse knot stabilizations,
and that it is non-zero for quasipositive braids. We also discuss a connection
to Heegaard Floer invariants.
