|0x0001 (1)| the read is paired in sequencing |读段序列是成对的
|0x0002 (2)| the read is mapped in a proper pair |读段定位在适当位置
|0x0004 (4)| the query sequence itself is unmapped |读段序列自身没有定位
|0x0008 (8)| the mate is unmapped |与其配对的读段为定位
|0x0010 (16)| strand of the query (1 for reverse) |读段对应链
|0x0020 (32)| strand of the mate |配对链
|0x0040 (64)| the read is the first read in a pair |读段是读段对的第一个
|0x0080 (128)| the read is the second read in a pair |读段是读段对的第二个
|0x0100 (256)| the alignment is not primary |定位不是最优选
|0x0200 (512)| the read fails platform/vendor quality checks |读段质量未生成
|0x0400 (1024)| the read is either a PCR or an optical duplicate |读段是PCR或者光学重复
这里就非常有意思了，需要自己去计算。比如值是1121 那这个值其实是由1024+64+32+1组成，这是唯一的，只能这一组的和。 然后分别就代表了 这只是一段PCR扩增产物1024+是read1序列64+ 正义链32+这是一个双端序列1 因此说bam文件记录了所有需要的信息。
