To improve chances of survival and response to treatment for life-threatening chronic diseases like cancer, detection of the early disease state is essential. MRI is the most beneficial imaging modality but due to the low sensitivity of current contrast agents, its capability for diagnosis is limited. Dr. Jenny Yang’s group has developed a novel protein-based MRI contrast agent with collagen- and HER2-targeting moieties, hProCA32.collagen1 and hProCA32.HER2, exhibiting high relaxivity, and improved sensitivity and specificity. The focus of this thesis is the optimization of hProCA32 purification by the addition of a refolding step, pH adjustment, and pre-loading of Gd³⁺, to yield ~90% monomer of a pure hProCA32.collagen1. The purified hProCA32.collagen1 was found to exhibit good collagen-binding affinity (1.8 µM) and high relaxivity (30.4 mM^-1s^-1 and 43.0 mM^-1s^-1 for r₁ and r₂) thereby suggesting that the MRI contrast agent may be useful to diagnose cancers at an early stage.