Abstract Sepsis is the leading cause of death in hospitals caused by a dysregulated host immune response to infection characterized by excessive neutrophil infiltration into vital organs, organ failure and death. Although blood tests relying on identification of pathogens are widely utilized to decide on treatment, they are severely limited by their ability to rapidly predict the onset, progression and recovery from sepsis. Hence, the goal of this proposal is to design, develop and demonstrate a rapid predictive assay using the native dysfunctional environment of the neutrophil observed in sepsis. This microfluidics-based assay provides quantitation of the neutrophil behavior for a predictive score reflective of the prognosis of the patient. Phase I will focus on validating our assay within 60 minutes with a sample population comprised of sepsis patients, SIRS patients, and healthy controls. Phase II will focus on building an instrumentation for the complete assay along with large patient study and plans for FDA approval.