Use this tool for masking hyper-variable regions from your alignment file. If your sequences are not yet aligned in the greengenes 7,682-character format, then first align them. Each correctly aligned sequence in your uploaded file will be compared to the Lane mask (Lane, 1991) to mask away (convert to hyphens) all but 1,287 conserved columns (lanes) of aligned characters. The resulting aligned fasta file will be emailed to you.