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Crucial positions

SBTengine indicates the crucial positions for allele assignment. It is important that the basecalling at these positions is correct since wrong basecalling at these positions will influence the outcome of the allele assignment. Therefore, it is strongly recommended that you check the basecalling at these positions before you approve the allele assignment. A list of crucial positions is given directly beneath the sample selection window.



You can easily scroll through the list with the up- and down arrow keys while SBTengine displays the selected position in the electropherogram for you to check. When you want to modify the basecalling at a crucial position, you may edit the nucleotide manually. When the basecalling at a crucial position is modified, SBTengine recalculates the near matches and crucial positions. New crucial positions will be shown in bold and are placed on the top of the list for you to check. Crucial postions shown in normal font are already reviewed by you. 

A list with near-matching genotypes is shown for each crucial position. When you mouse over a crucial position, all near matches are shown of that specific crucial position.



SBTengine lists all relevant nucleotide positions, which, if changed, will lead to another allele(s) assignment. The software takes a maximum of 3 possible nucleotide changes into account. When all crucial positions have been evaluated and all positions were clearly and correctly scored the allele assignment is ready.

In case there is no allele assignment, SBTengineŽ will show a list of crucial positions that you have to check. After each nucleotide that is edited the list will be updated and finally the correct allele assignment is shown. If applicable, SBTengine will show the crucial positions up to a maximum of 20 (!) possible nucleotides changes. 

In a few cases one or several sequences may have insertions or deletions (In/Del)) in the sequence that could not properly be managed by SBTengine. A message will appear in the lower right message box. You may solve this by manually evaluating the sequences and edit it accordingly or toggle off the sequence that contains the In/Del.