Showing posts from December, 2020

Creating Custom Database using Standalone NCBI BLAST+

Basic Local Alignment Search Tool (BLAST) is a collection of programs developed using heuristic algorithm in C++ for comparing DNA, RNA, and protein sequences. The standalone command-line interface (CLI) of BLAST is named as BLAST+. The latest version of NCBI BLAST+ can be downloaded from the FTP server of NCBI ( ). This is a simple tutorial for creating a custom database, accessing the database, and performing a sequence search using BLAST+. 1. Creating a Custom Database A nucleotide ( nucl ) or protein ( prot ) database can be created using -dbtype parameter in makeblastdb program. We can create two types of database using command-line below, Non-indexed Database: ./makeblastdb -in DBX.fasta -out DBX -dbtype prot Building a new DB, current time: 12/04/2020 10:10:06 New DB name: C:\NCBI\blast-2.6.0+\bin\DBX New DB title: DBX.fasta Sequence type: Protein Keep MBits: T Maximum file size: 1000000000B Adding sequences