Abstract: Disclosed herein are methods, biomarkers, systems, compositions and kits for determining the phase or metabolic state (e.g. First Phase, Second Phase, or Third Phase) of a red blood cell (RBC) sample or for determining the phase or metabolic state (e.g., First Phase or Second Phase) of a platelet (PLT) cell sample. The methods disclosed herein are related to the use of isolated RBC sample or isolated PLT sample and analytical tools for providing information that is relevant to the phase or metabolic state of the RBC sample or the PLT sample. The system disclosed herein utilizes isolated RBC sample or isolated PLT sample and at least one analytical tool or an output from the at least one analytical tool. The compositions and kits described herein utilize RBC samples or PLT samples, including compositions in a form that allows for analysis of the RBC sample or the PLT sample.