Katie Brenner in Lab (IMAGE) University of Wisconsin-Madison Caption Katie Brenner is pictured in the DeLuca Biochemistry Building with a prototype testing strip designed to detect estradiol and progesterone hormones in a woman's saliva, which can be used in conjunction with an app on a mobile device to measure fertility. Credit Bryce Richter/UW-Madison Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.