I am studying the role of soluble signaling factors in cancer development using the mouse breast cancer model. The study of soluble factors is complicated by several factors. First, many soluble factors are expressed at low levels and these factors are often dissipated in large culture vessels. We culture the cells within microfluidic channels in order to minimize the dilution of signaling factors that are expressed at low levels, providing an environment that more closely resembles in-vivo conditions.
The complex nature of cell culture media also posses a challenge. Typical media contains an assortment of proteins, growth factors, amino acids, lipids, carbohydrates, hormones, vitamins, and many other chemicals. Further, the concentration of these compounds ranges from ng/ml to mg/ml; low concentration species are difficult to measure due to both the limits of detection and masking by more abundant species such as albumin. I am currently evaluating sample preparation methods that can be used in conjunction with sensitive detection methods, such as mass spectrometry and fluorescence, so that we can study signaling factors that are expressed at low levels.