Hanks balanced salt solution with or without Ca2+ and Mg2+? - (Nov/30/2009 )

I need to use HBSS for preparing sheep red blood cells for T-cell rosetting. There are HBSS with calcium and magnesium and HBSS without calcium and magnesium. I am not sure which one I should use for this protocol. Anybody know? Thank you!

You need HBSS without Ca2+ and Mg2+. Because Ca2+ stimulate blood agglutination.

Thank you!