If you have extra blood in the syringe after filling the tubes as instructed and your kit has a 4 mL Green Top Tube, you can add up to 2mL of the excess blood left in your syringe to the Green Top Tube (this would total 4mL of blood in the tube, including the original 2mL of blood). Please be careful not to overfill this tube. If your kit has a 2 mL Green Top Tube rather than a 4 mL Green Top Tube, you can put the excess blood into a green top tube from your clinic. If you still have extra, please use a red top tube from your clinic for the remaining blood. If extra blood goes into a green top tube, that tube can be spun down, and the plasma can be transferred to the cryogenic tube using the green dotted pipette. If extra blood goes into the red top tube, that tube can be spun down, and the serum can be transferred to the white top tube using the red dotted pipette.