Using friend's urine got a quick question

if i have a urine test tommorrow and my friend pees in a bottle for me today what do i need to do to preserve it? are there any steps to take for keeping it fresh? i hear that urine can get old and they can detect that... i can have him piss for me tommorrow if anything but how long is it good for?

[edit]

i have just recieved the urine i stored it in a water bottle and it is currently sitting in my car. i recieved it at 8PM and now it is 9:20PM. unfortunatley he could only piss for me today because hes gonna smoke today and he hasnt in 6 months.

thanks in advance guys

freeze it ASAP

tomorrow morning, you will have to thaw it out, shake it up, and get it to about 100 deg. with hot water. It will begin to grow bacteria after about maybe 8 hours and may be good upto 18 hours. They will know if it is stale because of the bacterium.

if the urine was given to me at 8 pm . and i freeze it at 2 am will it be ok?

yeah but it would go bad after another 4 or more hours once thawed. How did u do?