barcodesDB • Generate Barcodes

Generate Random Barcodes

Generate random DNA k-mers matching your criteria. Does NOT query the bitmap. Use this if you want barcodes independently of the database.

Length (k)

Count

GC% min

GC% max

Must contain substring (optional)

Motif filters Off

Mode:

Filter homopolymer runs AAAAA…

Max run length:

Consecutive runs of the same base longer than this threshold. e.g., AAAAA (5 A's) fails with max=4.

Filter low-complexity sequences entropy

Min Shannon entropy:

Shannon entropy H = −Σ(p·log₂p). Max = 2.0. Sequences below threshold are flagged.

Filter common restriction sites 50 sites

Both forward and reverse-complement strands are scanned.

Flag short functional-like motifs 25 motifs

Conservative sequence patterns (TATA box, poly-A signals, CpG, etc.). Both strands scanned.

Filter dinucleotide repeats ≥6 bp

Detects ≥3 consecutive dinucleotide repeats (≥6 bp). e.g., ATATAT, CACACAC. Excludes homopolymer runs.

Filter trinucleotide repeats ≥9 bp

Detects ≥3 consecutive trinucleotide repeats (≥9 bp). e.g., CAGCAGCAG, ATCATCATC.

Filter tetranucleotide repeats ≥12 bp

Detects ≥3 consecutive tetranucleotide repeats (≥12 bp). e.g., GATAGATAGATA.

Filter custom sequence motif