F2 and blood coagulation disease: With an aim to provide an elaborate understanding of prothrombin time and related sensing platforms (PT assays), the following article enunciates the concepts of hemostasis and PT; clinical relevance of PT in thromboembolic complications and COVID-19 associated coagulopathy (CAC); lab-based PT/INR devices; point of care PT/INR assays; PT and associated protocols; and future prospects for PT sensing platforms and our conclusions about the future of this area.