JaMBW Chapter 2.1

Reverse, Complement, Inverse


Given a sequence of nucleic acids, this program generates its reverse, its complement, and its inverse into three independent windows. The above mentioned terminology is explained with the following example:

 5' ATATATCCCGGCG 3'     input sequence
 5' GCGGCCCTATATA 3'     its reverse
 5' TATATAGGGCCGC 3'     its complement
 3' TATATAGGGCCGC 5'     its inverse (say, reverse and complement) 

Mode of operation

This program uses 4 windows: the top one should be filled from the user, with a sequence of interest, while the other 3 windows contain the results of the operations. The following steps must be performed:

  1. Sequence input
  2. Case sensitivity choice
    Often is useful to mark regions of interest by changing the Case. This applet is capable of keeping those modifications also in its output, as well as to change the case of the sequence according to your wish. Therefore, by selecting anyone of the 3 choices provided, and hereafter described, the user has control on this aspect. In order to choose the case in the output, the following selections are possible, by clicking on the button close to them:
  3. Convert
    Once the sequence is placed in the top window, by pressing the "CONVERT" button then the conversion is performed.

A Java-enabled browser would have in this place a window similar to this picture:

How to understand its output

Since both aim and mode of operation are rather straightforward, also the understanding and the use of the results from this work should not present any major difficulty. The output will simply consist of the same sequence reverse, complemented and inverted as in the examples shown above.


  1. Watson,J.D. and Crick,F.H.C.(1953) Genetical implications of the structure of deoxyribonucleic acid. Nature,171,964-967.
  2. Nomenclature Committee of the International Union of Biochemistry (NC-IUB) (1985) Nomenclature for incompletely specified bases in nucleic acid sequences. Recommendations 1984.Eur-J-Biochem,150,1-5

Author:Luca I.G. TOLDO, Edition date: 28 February 1997