1. A kit comprising: (a) a substrate for holding a sample isolated from a subject; (b) an agent that specifically interacts with ubiquitin C-terminal hydrolase L1 (UCH-L1); (c) an optional additional agent that specifically interacts with at least one additional protein biomarkers upon contact with said sample; and (d) printed instructions for reacting the agent and the optional additional agent with the sample or a portion of the sample for diagnosing a neural injury or neuronal disorder in the subject.