Date of Award


Document Type



Santa Clara : Santa Clara University, 2018.



First Advisor

Ashley Kim

Second Advisor

Maryam Mobed-Miremadi


Breast milk, the gold standard for infant nutrition, could prevent up to 13% of child deaths worldwide. However, many mothers are unable to breastfeed due to health conditions and other factors. Because of this, a network of more than 500+ human milk banks, which collect and distribute donated breast milk to infants, have emerged worldwide. However, operational costs to ensure the safety of this milk remain time-intensive and costly.

There are no existing diagnostics for rapid and on-site detection of bacterial contaminants in donated milk. Currently, many milk banks send samples to outside laboratories for bacterial culturing tests, which take 24-48 hours to receive results. In contrast, MilkGuard is an on-site detection method which ensures results in hours rather than days. To determine whether or not E.coli is present in donated milk, a drop of milk is deposited onto the sensor. If the milk is contaminated, the sensor will turn a blue color due to an enzyme-substrate reaction of the bacteria.

The goal of the project is to create a cost and rapid alternative to traditional bacterial culturing testing to screen for E. coli bacteria in donated human breast milk. This will allow users to ensure that milk samples are sterile enough to provide to young infants, while also providing breast milk banks an alternative that will allow them to screen more samples in a shorter amount of time.