Acetoacetic acid, an endogenous metabolite found in cerebrospinal fluid and blood, is valuable for researching conditions such as meningitis, pregnancy, 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, preeclampsia/eclampsia, Diabetes Mellitus Type 2, glucose transporter type 1 deficiency syndrome, and succinyl-CoA:3-oxoacid-CoA transferase deficiency [1] [2] [3] [4] [5] [6] [7].