A few of the labs where I currently work routinely use 0.9% saline for in vivo work (washing out debris during surgery, diluting substances for IP/IV/SC injections, etc.)
A few years ago I worked in a lab where the standard was to use Ringer's Solution. Obviously, in both labs the choice was based on an organizatorical/historical reasons. But I was wondering: Does either of these solutions perform any "better" (i.e. causes less physiological disturbances) than the other?
My guess would be Ringer's is better, since it is also suitable for keeping cells alive in vitro - and there is also this paper that calls 0.9% Saline into question altogether. But I could not really find any good comparison tests.