The LadderFinder input is an Excel/OpenOffice spreadsheet. Genotypes are in the rows and SSRs in the columns. In particular, the first column should report genotype names and the first row SSR names. All the cells, but the ones in the first row and column, should contain the size of the two alleles, separated by a "-" (e.g. 168-174). Homozygous loci are equally represented by two alleles of the same size (e.g. 168-168). The following table is an input example.


To load the input table, select Open from the menu File on the top left of the main window. When the table is loaded, users can compute ladder simply by pressing the Compute button in the main window.

A new windows appears: the solution window.

The solution window contains two tabs:
  • Solution tab reports, for each SSR, the list of pairs of alleles that covers the maximum number of alleles represented in the database, with all alleles represented only once.
  • Cover tab shows, for each SSR, the minimum list of pairs of alleles that cover all the allele lengths.
Both of them contain one tab per SSR and report, in the first column, the selected pair of allele lengths and, in the second one, the code of the corresponding individual. Alternative individuals, that is individuals with the same allelic profile at a given SSR are reported in the next right cells. The last row shows the legths which are not present in the solution.

For instance, the computation over the above table returns the following tabs

It is possible to save both Solution and Cover tabs by choosing one of them and selecting Save form the menu File on the top left of the solution window. The saved table will contain either Solution or Cover tab in the same format of the solution window.