Related Experiment Videos
Microsatellite allele sizing: difference between automated capillary electrophoresis and manual technique
F Delmotte1, N Leterme, J C Simon
1UMR Biologie des Organismes et des Populations Appliquée à la Protection des Plantes, INRA, Le Rheu, France. delmotte@rennes.inra.fr
Biotechniques
|October 30, 2001
Summary
Automated sequencers show allele size discrepancies compared to manual methods. This bias in microsatellite sizing depends on locus size, highlighting the need for careful protocol descriptions and data sharing between labs.
Area of Science:
- Molecular Biology
- Genetics
- Bioinformatics
Background:
- Automated DNA sequencing technologies are widely used for microsatellite analysis.
- Discrepancies in allele sizing between different automated sequencers and manual methods have been observed.
- Understanding and quantifying sizing bias is crucial for accurate genetic data interpretation.
Purpose of the Study:
- To quantify the allele sizing bias introduced by automated capillary electrophoresis.
- To investigate the relationship between locus size and sizing discrepancies.
- To provide recommendations for improving inter-laboratory data comparability in microsatellite analysis.
Main Methods:
- Comparison of allele size data generated by multiple automated sequencers and a manual fragment separation technique (silver-stained polyacrylamide gel electrophoresis).
- Typing of 51 alleles across seven microsatellite loci.
- Analysis of the relationship between actual (manual) and called (automated) allele sizes.
Main Results:
- Significant discrepancies were found in microsatellite allele sizes between automated and manual methods.
- The observed sizing bias was inversely related to microsatellite locus size.
- The bias appeared independent of the fluorescent dye used but potentially related to differential migration patterns.
Conclusions:
- Automated capillary electrophoresis introduces a quantifiable sizing bias in microsatellite allele sizing.
- Distinguishing between actual (sequencing-confirmed) and called (sequencer-derived) allele sizes is essential.
- Standardization of material and protocol descriptions, along with sharing reference standard DNA genotypes, is critical for inter-laboratory data comparability and avoiding misleading conclusions.