BUSZ: Compressed BUS files

Summary We describe a compression scheme for BUS files and an implementation of the algorithm in the bustools software. Our compression algorithm yields smaller file sizes than gzip, at significantly faster compression and decompression speeds. We evaluated our algorithm on 533 BUS files from scRNA-seq experiments with a total size of 1Tb. Our compression is more than 2x faster than the fastest gzip option and results in 1.5x smaller files than the best gzip compression. This amounts to an 8.3x reduction in the file size, resulting in a compressed size of 122Gb for the dataset. Availability and Implementation A complete description of the format is available at https://github.com/BUStools/BUSZ-format and an implementation at https://github.com/BUStools/bustools Contact pmelsted@hi.is online.