The optimal time for blood collection is inthe morning after bed rest and overnight fasting. Fasting means not eating and drinking only water after 10 p.m. the night before.

Not being sober mainly affects the determination of substances resorbed from the diet as such (glucose, triglycerides, etc.). Indirectly, lipemic samples (elevated triglycerides) can technically interfere with the determinations. A number of parameters (e.g., iron, phosphate, cortisol) also show fluctuations during the day.

Depending on the type of study, midstream urine must be produced or first-voided urine:

Collection of midstream urine sample: for ordinary urinalysis

The examination requires the middle portion of the (best first morning) urine, called midstream urine.

For women:

• Beforehand, wash the pubic area with a washcloth with water:
• Spread the labia and clean with water (no soap!) or with a damp cloth (always from front to back) and dry with toilet paper.
• Keep the labia spread when urinating.

For men:

• Pull the foreskin back and clean with water(no soap!) and dry with toilet paper.
• Hold the foreskin back when urinating
• First pee a little in the toilet and then collect some urine in a clean urine jar by holding it in the urinal.
• Then close the jar tightly with the lid.
• If necessary, write your name and date of birth on the jar and store it in the refrigerator.

Collection of“first void” urine sample (for STD testing):

First void urine means first discharged urine (first void = first 10 to max. 20 ml). Patients should not have urinated in the last two hours before collection (so preferably morning urine = first urine when getting up). Only the first 20 ml should be collected. The rest of the urine is further urinated out in the toilet.

If first-void morning urine is not possible, urine may also be made on site provided no urination has occurred in the last 2 hours. This first-void urine (only the first 20 ml of the urine stream; rest back out in toilet) should be collected in a sterile urine container.