DNA and samples requirements Back to top

• What is the required DNA quality for DArTseq?

  For DArTseq the DNA needs to be suitable for digestion by restriction enzymes and ligation to adaptors. Good quality DNA is always the best assurance of good outcome of the service.
  Obtaining higher purity DNA has the following long term advantages:

  • Improved shipping endurance;
  • Improved storage duration;
  • Higher data quality and volume; and
  • Broader usage over multiple tests and assays, over a longer time period.

  In the last several years we have processed samples extracted with a very broad range of methods, both “in-house” procedures, predominantly CTAB-based, and a large diversity of commercial extraction kits.

• Does SEQART offer DNA extraction service?

  Yes, many of our clients use our DNA extraction service. When our clients experience difficulties with obtaining good quality DNA we usually find a way to bring those samples in using our Import Permits. Please inquire about your specific case and we will provide recommendations.

• How do you control DNA quality?

  We recommend using the following protocol prior to sending the samples to us. This will help you receive the best quality data for your samples in less time, preventing you from having to resend those samples of poor quality if any.

  DNA quality of the samples is controlled by:

  • Incubating 1µl of DNA in Restriction Enzyme buffer at 37°C for 2 hours.
  • Resolve the DNA on a 0.8% agarose gel in 1x TAE buffer.
  • Inspect the gel image for your samples. Good quality DNA gives a high molecular weight band on the gel image.

  This protocol is a mock digest to detect the presence of buffer-activated (usually Mg dependent) nucleases: no restriction enzyme is used.

  Another option for you is to send us the image of the DNA quality control you already have, for us to ensure the DNA is of sufficient quality for DArT genotyping.

• How much DNA do you need to provide?

  To perform a DArT assay, we require you to send us about 20µl of an aqueous solution of DNA at 50 to 100 ng per µl, not more. Excessive concentration is detrimental to the assay. If your DNA is concentrated please dilute it.

  The assay itself uses 2µl of recommended concentration DNA, however we require a larger volume to reduce problems during shipment and to be able to perform Quality Control/Method Test (for new organisms).

  We were able to process samples with much lower DNA concentration than recommended, including DNA extracted from museum and herbarium specimens often over 100 years old, but the best data quality is assured by providing samples in recommended range. Our assays generally tolerate up to 3-4 fold variation in DNA concentration within a plate.

  Please contact us if you have any questions regarding the quality and/or quantity of your samples DNA

• Should I control my DNA before shipment? How?

  Definitely, as you would save time and money if you check your DNA before shipping it to us.

  We suggest that you follow the QC procedure we use (see above), testing for the quantity and quality of DNA as well as the lack of nucleases, on an agarose gel.

  You may want to control further the suitability of the DNA for DArTseq by testing the digestibility of the DNA using a frequently cutting (e.g. 4bp recognition site) restriction enzyme, always running side by side cut and uncut DNA, in the same buffer.

• How do I pack my DNA for a shipment?

  You can find all relavent information for packaging orders on at  https://ordering.seqart.net/cgi-bin/order/login.pl .This includes how to package your DNA orders.

  At SEQART we try to expedite processing your orders as quickly and efficiently as possible, yet we still receive samples poorly packed or missing paperwork. Please contact us if you have any doubts or questions.