Fragment analysis measures the size of DNA fragments by comparing the unknown fragment to DNA fragments with known lengths (the size standard). The size standard is combined with the sample and co-injected for capillary electrophoresis. Common applications include: DNA fingerprinting, parentage analysis, microsatellites analysis, AFLP and ARISA.
To ensure that you obtain high quality data, it is essential that you have a robust PCR reaction that amplifies the target consistently across your samples. The PCR products should be strong (concentrated) and require a considerable dilution before sample submission (e.g. 1 in 100). The dilution is intended to avoid over-saturation of signals and to dilute out common contaminants. Excess reagents and salt can interfere with the electrokinetic injection of the machine and lower the quality of the data. Other contaminants, such as residual protein or detergents carried over from DNA extraction can adhere to the capillaries of the array thereby adversely reducing the quality of the data. If a considerable dilution of the sample is not possible, we require our customers to perform a cleanup step (e.g. ethanol precipitation) prior to submission.
Very strong signals are difficult to analyse and have a similar negative impact to contaminants. We suggest that clients perform a serial dilution (e.g. 1:20 to 1:150 ) on a subset of their samples to optimise input. If the size range and fluorescence label do not overlap, multiple targets with the same fluorescence label may be pooled or a multiplex PCR can be performed.
Please download our user guides for detailed instructions on how to use our Sanger sequencing services:
- Sequencing Guide – will provide you with a step-by-step guide to sample preparation.
- dnaLIMS User Guide – will walk you through creating an account in dnaLIMS and submitting samples online.
Returning customer? Login in to dnaLIMS to submit your samples.
Available Size Standards:
You will receive an email notification once processing is complete, you will then be able to access your data via your dnaLIMS account.
Free re-run service if results do not meet our quality standards
Note: Working days are Monday – Friday. Samples must be received by 12 noon to be included in the days processing list.