Filter Protein Sequence

This tool removes any non-protein characters from a string of text representing an amino acid sequence. It provides options for which characters to filter out, what characters -if any- to substitute the removed characters with, and what case (upper or lower) to output the resulting string in. The tool also determines whether or not the provided amino acid string is valid based on the filtering criteria selected under the filter criteria.

Filter Criteria:

Substiture Character:

Output Case (upper/lower):

Feedback

Have a question or a feature request about this tool? Feel free to reach out to us and let us know! We're always looking for ways to improve!

Email address

References

This online resource may be cited as follows

MLA	"Quest Calculate™ Filter Protein Sequence." AAT Bioquest, Inc., 14 Jan. 2026, https://www.aatbio.com/tools/quick-calculator/filter-protein.
APA	AAT Bioquest, Inc. (2026, January 14). Quest Calculate™ Filter Protein Sequence. AAT Bioquest. https://www.aatbio.com/tools/quick-calculator/filter-protein.
BibTeX	EndNote	RefMan

Amino Acid Abbreviations
Convert between 3 and 1 letter formats (e.g. Trp and W)
Codon / Anticodon
Convert between codon and anticodon sequences
Degree of Labeling Calculator
Characterize bioconjugates by calculating the number of labels per target on average
Filter Protein Sequence
Verifies protein sequence and removes invalid characters
HABA Biotinylation Calculator
Use absorbance to determine quantity of biotin in a sample
Michaelis-Menten Kinetics
Determine reaction velocity of a substrate

Related tools