SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) also known as 2019-nCoV (2019 Novel Coronavirus) is a virus that cause illness ranging from the common cold to severe diseases. SARS-CoV-2 Spike Protein is derived from 2019-nCoV, which is composed of a S1 domain and S2 domain. The S1 contains a receptor-binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. It was believed that SARS-CoV-2 Spike Protein (RBD) has potential value for the diagnosis of the virus.