Microfluidic Device Media Collection and PRL ELISA Assay Protocol

Collect the spent media from the outlet reservoir of the microfluidic device into centrifuge tubes at the specified collection time point. Centrifuge the tubes at 300g for 10 minutes to eliminate any cell debris. Test the samples immediately or store them at -80°C until further use. The amount of PRL secreted in the culture media was measured using ELISA, following the manufacturer's instructions. Dual-wavelength detection was performed using an enzyme labeler and a microplate reader to determine the OD values at the maximum absorption wavelength of 450 nm and the calibration wavelength of 630 nm. The protein concentration was determined using logistic regression analysis.