软件下载解压后，直接运行会有个报错提示，按照报错提示运行即可，会有个窗口弹出，确定即可
#Shell：下载命令
sratoolkit.2.10.8-ubuntu64/bin/prefetch --option-file srr.list #srr.list为SRR8737281等编号，可以从SRA数据库中下载下来metadata文件
#metadata示例下载链接
https://www.ncbi.nlm.nih.gov/Traces/study/?query_key=1&WebEnv=MCID_6020aa1fa1a099321f718b0a&o=acc_s%3Aa&s=ERR2103489,ERR2103490,ERR2103501,ERR2103502,ERR2103503,ERR2103504,ERR2103505,ERR2103507,ERR2103508,ERR2103510,ERR2103512,ERR2103522,ERR2103523,ERR2103524,ERR2103525,ERR2103526,ERR2103527,ERR2103528,ERR2103530,ERR2103531,ERR2103532,ERR2103506,ERR2103491,ERR2103493,ERR2103494,ERR2103495,ERR2103496,ERR2103498,ERR2103499,ERR2103513,ERR2103514,ERR2103516,ERR2103517,ERR2103519,ERR2103492,ERR2103511,ERR2103521,ERR2103497,ERR2103520,ERR2103509,ERR2103500,ERR2103515,ERR2103518,ERR2103529
#注意：SRA文件名称不一定是SRR开头，也可以如ERR2103489
#Shell：转换sra文件为fastq格式
bin/fastq-dump --split-files --gzip SRR8737694/SRR8737694.sra
#输出：对于PEreads输出 SRR8737694_1.fastq.gz和SRR8737694_2.fastq.gz
体会：两个文件大小加起来比sra文件大一些，从节省存储角度看，二进制SRA文件可以“经济实惠”，用的时候再解压即可
