Overview of Essential File Formats in NGS Data Analysis
FASTQ Files
Raw sequencing output is typically stored in FASTQ format, frequently compressed as .fq.gz. Each read occupies four lines:
Line 1: identifier starting with @
Line 2: nucleotide sequence
Line 3: a separator (usually +)
Line 4: per‑base quality scores (ASCII-encoded)
Common inspection commands:
# Display the first two reads
zcat sam ...
Posted on Thu, 30 Jul 2026 16:49:04 +0000 by willchoong