Learn genomics
Short explanations of genomics and bioinformatics concepts used in sequencing and variant interpretation.
Human reference genomes quick reference
A human reference genome defines the coordinate system used to map sequencing reads and report variants. Multiple bui...
What is a BAM file?
A BAM file is the compressed binary form of a SAM file, used to store sequencing read alignments to a reference genom...
What is the BED format?
BED (Browser Extensible Data) is a text-based file format used to describe genomic regions or features using chromoso...
What is the CRAM format?
CRAM is a compressed file format used to store sequencing read alignments, designed to reduce storage size compared w...
CRAM vs SAM vs BAM explained
SAM, BAM, and CRAM are file formats used to store sequencing reads after they have been aligned to a reference genome...
What is the CSI index format?
CSI (Coordinate Sorted Index) is a genomic index format that enables fast access to regions within large coordinate-s...
What is the FASTA format?
FASTA is a text-based file format used to store biological sequences such as DNA, RNA, or proteins using standard sin...
What is the FASTQ format?
FASTQ is a text-based file format used to store sequencing reads together with a quality score for each base, allowin...
GRCh37 vs GRCh38 reference genomes explained
Human sequencing data are aligned to a reference genome that defines genomic coordinates. GRCh37 and GRCh38 are the t...
What is the SAM format?
The SAM format (Sequence Alignment/Map) is a text file format used to store how sequencing reads align to a reference...
What is Tabix indexing?
Tabix is a tool and index format that allows fast retrieval of genomic regions from large, position-sorted text files...
What is a VCF file?
A VCF file (Variant Call Format) is a tab-delimited text format that records genomic variant sites, the alleles obser...
VCF vs gVCF explained
A VCF records positions where variants were detected in a genome, while a gVCF records both variant sites and regions...
