  We demonstrate generation of an isotopically pure beam of laser-cooled Yb
atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal
beam are first slowed using a Zeeman Slower. They are then subjected to a pair
of molasses beams inclined at $45^\circ$ with respect to the slowed atomic
beam. The slowed atoms are deflected and probed at a distance of 160 mm. We
demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the
fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses
beams are turned on, we find a longitudinal temperature of 41 mK.
