An identity threshold must be specified using the -id option. If full-length, exact matches are required, then it is better to use search_exact than usearch_global with -id 1.0.
The query file may be in FASTA or FASTQ format.
A database file must be specified using the -db option. FASTA and .udb formats are supported. For large databases, .udb format is recommended (see makeudb_usearch command).
The -strand option is required for nucleotide databases.
Nucleotide, protein and translated searches are supported.
See also
Output files
Accept options
Weak hits
Termination options
Indexing options
Multithreading
Masking options
Alignment parameters
Alignment heuristics
Examples
usearch -usearch_global query.fasta -db proteins.udb -id 0.8 -alnout hits.aln
usearch -usearch_global reads.fastq -db ESTs.fasta -id 0.9 -blast6out hits.b6 \
-strand plus -maxaccepts 8 -maxrejects 256