CKMT1A (creatine kinase mitochondrial 1A) and CKMT1B (creatine kinase mitochondrial 1B) are isoforms of the mitochondrial creatine kinase (CK) system, encoded by the *CKMT1* gene through alternative splicing. These enzymes play a critical role in cellular energy metabolism, particularly in tissues with high energy demands like skeletal muscle, heart, and brain. They catalyze the reversible transfer of phosphate between ATP and creatine, maintaining energy homeostasis by buffering ATP levels and facilitating intracellular energy transport. CKMT1A is ubiquitously expressed, while CKMT1B is predominantly found in the brain and reproductive tissues. Both isoforms localize to the mitochondrial intermembrane space, where they interact with the inner mitochondrial membrane to support oxidative phosphorylation and ATP synthesis. Antibodies targeting CKMT1A/CKMT1B are essential tools for studying their expression, localization, and functional roles in physiological and pathological contexts, such as neurodegenerative diseases, cardiac ischemia, and cancer. These antibodies enable detection via techniques like Western blotting, immunohistochemistry, and immunofluorescence, aiding research into mitochondrial dysfunction and metabolic disorders. Specificity validation is crucial due to sequence homology between isoforms and other CK family members.