Precision medicine requires high throughput cell isolation and measurement that maintains physiology. Unfortunately, many techniques are slow or alter cell biomarkers cells.This necessitates new approaches, which we achieve by integrating affinity-based cell isolation with spiral microfluidics. We characterize the device via computational simulations, predicting wall shear stress within an order of magnitude of arterial wall shear stress (~0.2 Pa). We identify that poly-L-lysine supplementation preserves cell geometry and improves cell release. We demonstrate preservation of angiogenic biomarker concentrations, measuring 1,000-2,000 vascular endothelial growth factor receptor-1 per human umbilical vein endothelial cell, which is in line with the previously reported measurements. We attain 76.7 ± 9.0% release of captured cells by integrating thermophoresis and optimizing buffer residence time. Ultimately, we find that combining affinity-based cell isolation (secondary anchor targeted cell release) with spiral microfluidics offers a fast, biomarker preserving approach needed to individualize medicine.