title: High through put sequence of NifH gene: Sample S1SP
design: "For genomics DNA, we use fusion primer with dual index and adapters for PCR, fragments too short would be removed by Ampure beads too. In both cases, only the qualified library can be used for sequencing. In order to obtain more accurate and reliable results in subsequent bioinformatics analysis, the raw data will be pre-processed to get clean data by in-house procedure as following:(1) Truncation of sequence reads not having an average quality of 20 over a 30 bp sliding window based on the phred algorithm, and trimmed reads having less than 75% of their original length, as well as its paired read, will be removed;(2) Removal of reads contaminated by adapter(default parameter: 15 bases overlapped by reads and adapter with maximal 3 bases mismatch allowed);(3) Removal of reads with ambiguous basa(N base), and its paired reads;(4) Removal of reads with low complexity(default: reads with 10 consecutive same base). For pooling library with barcode samples mixed, the clean reads were assigned to corresponding samples by allowing 0 base mismatch to barcode sequences with in-house scripts."