Genomic DNA (gDNA) Quality and Quantity Requirements

Genomic DNA (gDNA) Quality and Quantity Requirements

For DArT genotyping assays we recommend 500–1000ng of restriction enzyme grade genomic DNA (gDNA), resuspended in aqueous solution as EB buffer at a concentration of 50–100ng/µl. Other acceptable solutions are Molecular Grade water and TE buffer with lowered EDTA concentration.

If you have less gDNA than recommended quantities please contact us at samples@diversityarrays.com. We may still be able to process your samples as we successfully produced genotyping data from samples with concentration less than 10ng/µl.

DArT assays tolerate well up to five fold differences in gDNA concentration, however the more uniform gDNA concentration of submitted samples the better quality of genotyping data.

Please be aware of additional fee incurred if gDNA concentration variation exceeds acceptable levels (up to 5 fold) and we need to adjust the gDNA concentration before the carrying out the assays.

We use 2µl gDNA of recommended quality/quantity per assay, therefore:

  • for organisms/products listed in our system please submit at least 10µl of gDNA of required concentration, although 20µl is recommended.
  • for new organisms/products please submit minimum of 20µl of gDNA of required concentration, however higher volumes up to 50µl are welcome.

In any case do not exceed 70µl gDNA as it significantly increases the risk of sample cross-contamination during shipment and handling.

As for all genotyping methods, gDNA quality has a major effect on genotyping data quality. Therefore, we recommend performing gDNA ‘mock incubation’ test of the samples before shipping them to us, even if it is on a subset of the samples. Please perform ‘mock incubation’ test as follows: incubate 2µl of gDNA in Restriction Enzyme buffer at 37°C for 2 hours and then resolve the samples on a 0.8% TAE agarose gel. Good quality gDNA gives a high molecular weight band on the gel.

gDNA derived from museum collections/valuable/prolonged storage materials

If you are submitting gDNA derived from museum collections/valuable/prolonged storage materials, irrespective of expected quality/quantity, please ensure you alert us by adding adequate note while placing your order and on the Sample Tracking File in the Comments.

If you require any additional information about your gDNA quality/quantity please contact us at samples@diversityarrays.com.

Suggested, not automated methods of gDNA extraction can be found below:

This method proved to work well for many plant species: https://www.diversityarrays.com/orderinstructions/plant-dna-extraction-protocol-for-dart/.

There is also alternative method developed by one of our collaborators, which should work equally well: https://www.diversityarrays.com/orderinstructions/extracting-dna-from-plants-alternate/.

Please note that we cannot guarantee that these methods will work for any species.