As you may remember from biology class, biological females have variation in hormones across the menstrual cycle. The exact length of the hormone cycle and the levels of hormones vary between women** and across an individual woman’s life. How this variation in circulating hormones might affect other physiological systems and ultimately health outcomes is a complex and understudied area. A major part of our research projects is that we are interested in how hormones and biomarkers vary for women across the menstrual cycle. This means we need daily measures of hormones from each woman who participates in our studies. For our current project based in Poland, we ask each woman to collect urine each morning.
In the past, the best way for us to collect, store, and ship these samples back to our lab would be for the women to use a normal 4 oz (188 mL) urine collection cup. This is just like the kind you might use at your doctor’s office.
It is important for the urine to be frozen right away, and using this type of cup really fills up a woman’s freezer! After one full menstrual cycle, our research participants could have 20-36+ small cups of urine in her freezer, with a total volume of 2-3 liters! That can be a problem, especially in the smaller freezers that are more common in the region in which we work.
Fixing the freezer space problem
Our first idea was that we could collect the cups periodically from each woman and aliquot some into smaller containers using a standard plastic pipette. This would take a lot of time for us, because we would be walking to their houses or the local clinic, thawing the samples, aliquoting, and refreezing. Let’s not even discuss how we were trying to figure out if there was clinic space for the aliquoting or if we would have to do this on the dining room table at our field site residence!!!
Then our field site manager/coordinator/hero Andrzej Galbarczyk enters the scene and argues that we should use some fancy new urine collection cups. As we Americans scoff at the idea over Skype, Andrzej insists that the cost is not much higher, the process will be easier, and he can order them to be shipped directly to the field site for us. Katie admits, it was that last part that sold her on the idea. She couldn’t figure out how we would fit 15 x 30 urine cups + 15 x 30 pipettes + 15 x 30 x 3 small tubes into the checked luggage for the trip to Poland. We needed to bring a lot of shoes and clothing to be prepared for walking up and down the mountains in a variety of weather conditions.
|The fancy new collection cups.|
That’s how we recall being talked into the new urine collection system. The urine cups have a fancy little lid that screw on securely (after you fill it), which then allows you to use vacuum tubes to take aliquots of urine from the cup. Vacuum tubes are commonly used in the US for blood collection. You may have seen your phlebotomist use them the last time you had to have blood drawn at the doctor’s office. Our vacuum tubes for urine have a special yellow top to help distinguish the contents.
Of course, before we could ask our research participants to use these fancy cups, we had to test them ourselves. This is also when we nicknamed our urine cups. Fieldwork + jetlag does funny things to your mind. To test our urine cups, we bought some Polish apple juice (gotta support the local economy!), filled the cups, and then filled up some vacuum tubes.
These fancy urine cups were thus dubbed “kubki Ferrari”, or “little Ferrari cups” since they were so fancy and from a company based out of Italy. Everyone who visited the field site over the summer got a chance to either try the cups for themselves (with apple juice) or see a demonstration. One lucky soul even had the opportunity to use our test-frozen sample tube to reduce inflammation on a foot injury.
|Our test to verify that the tubes would freeze without breaking. Full of sok jabłkowy (apple juice).|
* Reference to Rocky and Bullwinkle title formats
** We are using the colloquial gendered term “women” instead of the biological term “female”. We understand that there is huge diversity in how people may identify their gender.