Basophils are rare (~1% of peripheral blood leukocytes), yet potent effector cells that initiate and perpetuate a wide range of immunological responses. In particular, the role of basophils in food allergy is widely studied and has led to the emergence of a highly accurate ex vivo diagnostic test for food allergy: the basophil activation test (BAT). In contrast to commonly used food allergy diagnostic tests, i.e., skin prick test (SPT), allergen specific IgE (sIgE) measurement, and oral food challenge (OFC), the BAT provides highly sensitive and specific results (more than 90% across a range of allergens) while not subjecting individuals to potentially unsafe outcomes (e.g., anaphylaxis). Furthermore, basophil reactivity measured with BAT correlates well with severity and can be used to predict allergen thresholds that elicit a reaction in OFC. Despite the advantages of BAT over other methods, translating it to common clinical practice has been hampered. Motivated by the potential that BAT presents for changing the paradigm of food allergy diagnostics, my thesis dissertation focuses on various microfluidic approaches and aspects of measuring basophil activation that aim to increase clinical accessibility to BAT and to other future assays that probe basophil function. First, I investigated the utility of avidin as a basophil activation marker to evaluate whether avidin could enhance the predictive capability of BAT. Next, I developed various methods for rapid immunomagnetic isolation of basophils from whole blood to enable BAT-based diagnostic approaches and research that require purified basophils. Finally, I developed and characterized a novel device and analysis pipeline for increasing the clinical accessibility to BAT. Where applicable, I used computational methods to inform the design of the devices and analyzed data with machine learning.