Beckman Coulter CEQ 8000, User Manual

Page: 266 / 382

Fragment Analysis Procedures
252 CEQ™ 8000 Genetic Analysis System
The only time that “Use +A peak to call allele” is checked while the
“/-A” is not checked is when there is complete conversion of
the PCR product to +A. When neither “Use +A peak to call allele” nor
“/-A” are checked, no +/-A labeling will occur.
In general, the reproducibility of size estimates is better for higher peaks than for
lower peaks. Therefore, it is good practice to direct the software to use the higher of
the peaks associated with the allele to identify the allele.
Additionally, it is generally a good idea to check the “/- A” option so the
software will correctly categorize peaks. If the option is incorrectly configured, the
alleles will still be identified, but the +A and -A peaks are frequently categorized as
unknown alleles and the software will report “Too many alleles” in the Comment
column of the fragment data table.
Use +A Peak to Call Allele
Not Checked
All fragments assumed not to be +A.
Any fragments wA are
identified as the allele in the allele
table.
Fragments with +A are identified as
+A peaks or spurious peaks. All fragments assumed not to be +A.
Any fragments wA are
identified as the allele in the allele
table.
Fragments with +A are identified as
unknown alleles or spurious peaks.