SERV   Sequence-based Estimation of Repeat Variability

Please refer to our Genome Research paper:

Legendre M, Pochet N, Pak T and Verstrepen KJ 
Sequence-based estimation of minisatellite and microsatellite repeat variability
Genome Res. 2007 17: 1787-1796

The Verstrepen Lab
   (Harvard FAS Center for Systems Biology)


SERV was trained on a dataset containing naturally occurring repeats. As a result, SERV predictions can only be trusted for repeats that fall in the range of commonly occurring repeats. The variability of some extreme repeats (i.e. repeats with an unusually high number of units) is not estimated correctly.

More specifically, repeats with unit sizes of 2-10 nucleotides should have no more than 90 units; repeats of unit size 20 should not have more than 80 units, and repeats with units of size 75 nucleotides should not have more than 20 units. SERV will never accurately predict the variability of repeats with units longer than 75 nucleotides. For these rare repeats, we recommend using the TRF score as a crude estimation of variability.

SERV will warn the user when the input repeat sequence is out of the operating range.

Predict Tandem Repeats and Variability

Paste your sequence(s)


Choose a file to upload

(Fasta format)


(Fasta format)


Tandem Repeats are detected using Tandem Repeats Finder (Benson et al)
TRF parameters: match=2, mismatch=5, indels=5, match probability=0.8, indel probability=0.1, score cutoff=40

Benson G.
Tandem repeats finder: a program to analyze DNA sequences. Nucleic Acids Res. 1999 Jan 15;27(2):573-80.

Predict Variability from Tandem Repeats Characteristics

Tandem Repeats are defined by:
-  Repeat Purity (overall percentage of matches between copies (range 0-100)
-  Unit size (in nt.)
-  Number of units

Paste Tandem Repeats Characteristics


Choose a file to upload

(Repeat Purity, Unit Size and Number of units)
separated by spaces or tabulations
(one repeat per line)


(Repeat Purity, Unit Size and Number of units)
separated by spaces or tabulations
(one repeat per line)