In keeping with SARS CoV, many cleaved and uncleaved forms of the SARS-CoV-two spike protein. Notably, the cleavage sample for the the SARS spike constructive control from Calu3 cells, a respiratory cell line, differs slightly and will signal discrepancies between proteolytic cleavage of the spike proteins amongst the two viruses https://www.pinterest.com/pin/993958580252574867/