sentence: Several TGS platforms have been released , including : ( i ) true single-molecule sequencing ( tSMS ; Helicos BioSciences ; Cambridge , MA , USA ) ; ( ii ) single-molecule real-time ( SMRT ; Pacific Biosciences ; PacBio ; Menlo Park , CA , USA ) ; ( iii ) combinatorial probe-anchor ligation ( cPAL ; BGI Group-Complete Genomics ; Shenzhen , China ) ; and ( iv ) nanopore ( NP ) sequencing ( Oxford Nanopore Technologies ; Oxford , UK ) .