MCPyV DNA sequence analysis and alignment of MCPyV Tag nucleotide sequences. (A,C) nt 571 to 879 and nt 1709 to 1846 from the MCC350 strain, respectively, compared with the MCC339, United States isolate, the TKS Japanese isolate, and the MKL-1 Swedish strain. Nucleotide substitutions/deletions (−) in different MCPyV strains are marked in gray. (B,D) nt 571 to 879 and 1709 to 1846 from the MKL-1 strain, respectively, compared with sequences obtained from buffy coats (B.C.). Seven of 10 DNA samples from B.C. contain a single nucleotide substitution, which is cumulatively marked in gray in the same sequence (B, B.C.).