It is that quantity of urine passed by a person during a period of 24 hours.
The collection period usually starts in the morning. When you first get up (say 6 am), empty your bladder, but do not collect this urine. Note down that time to mark the beginning of your 24 hour collection period. For the next 24 hours, collect all the urine whenever you pass. However you should empty your bladder for the final collection at or just before the end of the 24 hour collection period (6 am). Add the final sample to the large container and record the time.
Your doctor or Lab will provide you with a large container that can hold upto 5 liters.
No, you cannot use any other container because the container should be sterile and should contain some amount of preservative or stabilizers in it to maintain the condition of the sample. Avoid touching the inside of the container with your fingers.
Yes, it is possible for males to collect the urine directly into the container, but females should first collect the urine in a small clean container called urine measuring jar (Which can be purchased from the pharmacy) and then pour it into a large container immediately.
Keep the large container in a cold place during the collection period. Avoid contaminating the sample with toilet paper, pubic hair, faeces, menstrual blood or other foreign matter.
If any voided urine is not collected during the 24 hour collection period, that days collection is not valid. Abandon collection for that day and start fresh collection in a new container from next day.