Im unsure as to the point of this question. Are you checking up on the injector who did your botox or are you thinking of mixing your own. The question as stated doesn't make sense -- 1.5cc of saline mixed with 50u of botox pulled into a 5cc syringe means that all 1.5 cc with the 50 u is now in the 5cc syringe. Its like asking what color was George Washington's white horse or who is buried in Grant's tomb. Im not making light of your question, Im just concerned.If you are trying to check up on your injector, please give him or her a call and make a follow up appointment to review what was done. A reputable physician will have documented the dilution, lot number and number of units used. If you are considering mixing your own, please do not do it. Botox is not a cosmetic. It is a drug that should only be administered by physicians who understand anatomy and drug chemistry.Please find a board certified cosmetic dermatologist if you don't already have one.I hope this answer was helpful. Best of luck