Genome sequencing analysis turns the raw DNA reads from a sequencer into a filtered, annotated catalogue of variants and a biological interpretation of what they mean. The instrument produces billions of DNA letters in FASTQ files; whole genome sequencing analysis is everything that follows, from aligning those reads to a reference through calling and filtering variants to annotating their effect. This guide walks the pipeline for both eukaryotic and bacterial genomes and explains where the decisions that determine a trustworthy result actually sit.
If you have whole genome sequencing data and need variants called and annotated, or a set of bacterial isolates turned into a phylogenetic tree, this guide shows what a complete DNA sequencing analysis involves and how to keep it reproducible and defensible.
What Genome Analysis Is Trying to Find
A genome is mostly identical between any two individuals of a species; the interesting biology lives in the differences. Genome sequence analysis is therefore largely the business of finding and interpreting those differences, the variants: single-base substitutions, small insertions and deletions, and larger structural changes. For a human study, that means cataloguing how a sample's genome departs from the reference and predicting which of those departures matter. For a set of bacterial isolates, it means comparing genomes to each other to reconstruct how strains are related and what resistance or virulence genes they carry.
Because the reference build and annotation databases define the coordinate system and the meaning of every variant, a variant call is only interpretable alongside the exact versions used. Pinning and documenting them is not bureaucratic; it is what makes the result reproducible at all.
The Whole Genome Sequencing Pipeline
The reference-based pipeline for human and other eukaryotic genomes is well established and runs through these stages.
