There are TB kits that contain three special tubes individually wrapped in a small biohazard bag usually in the cabinet of the Labs TS room. If you can't find one in the Labs TS room or the clinic, go to IMA Saturday clinic next door and ask the IMA Labs nurse for the tubes if they have any.
There are 4 tubes in this kit. The order in which you draw the tubes is not important.
Draw up 1mL of blood (up to the black mark on the side of the tube -- the tubes seemed to be pressurized to a point that blood stops flowing well once they have reached that level anyway) into each tube.
Gently shake the tubes so that all of the sides are covered.