DArT markers can be used in Marker Assisted Selection (reference). Using the sequence of the DArT marker of interest, you will need to establish a monoplex assay. This will usually require the sequencing of the genomic region of interest, the identification of an appropriate sequence polymorphism in that region and the design of an assay (nearly always a PCR-based assay) to type this polymorphism.

Before you embark into the significant work required to establish one or a few monoplex assays, you may want to consider carefully your needs in terms of density of information you require. We can provide low-density (100-400 markers) DArT assays customised to your application if the demand for the assays is sufficient. The low-density assay can type a small number of genomic regions of interest together with some framework genotyping useful for quality control.

The DNA needs to be suitable for digestion by restriction enzymes and ligation to adaptors.

Although more work is required to prepare it, investing in high purity DNA is advantageous in the long term: it ships better, stores better, provides more (and higher quality ) data, and can be used for mutiple tests and assays, over a long time.

View a suggested DNA extraction protocol.

View another suggested DNA extraction protocol.

DNA quality is controlled upon arrival of the samples by incubating 1 µl of DNA in Restriction Enzyme buffer at 37°C for 2 hours and then running the DNA on a 0.8% agarose gel. Good quality DNA gives a high molecular weight band on the gel. This is a mock digest to detect the presence of buffer-activated (usually Mg dependent) nucleases: no restriction enzyme is used.

To perform a DArT assay, we require that you send us about 10-20 µl 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: dilute it.

The assay itself requires less than one microliter but we need a larger volume to reduce problems during shipment and to be able to perform Quality Control.

DArT markers are sequence-ready and can be quickly sequenced when the need arises.

For Barley, Oats, Sorghum, Sugarcane, Cucumber and Wheat, most markers have been sequenced. We are nearing completion of sequencing apple markers (approximately 3,000), eucalyptus (>7,000) and progressing with sequencing markers from many other species (e.g. potato, lolium, festuca, cassava, triticale, cotton, rye etc.) Prior to their publication, sequences are available upon request.

For other species, sequencing will be organised as demand for the data increases.

You would save time and money if you check your DNA before shipping to us. We suggest that you follow the QC procedure we use, testing for the presence and quantity 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 DArT, by testing the digestibility of the DNA using restriction enzyme PstI and/or a frequently cutting enzyme, always running side by side cut and uncut DNA, in the same buffer.

A complete DArT assay from QC-passed DNA to data can take as little as 3 days.

Of course we try to service many users at the same time, so our genotyping service aims at delivering data to the customers within 8 weeks of receiving suitable quality DNA.

We accept for payment, in order of preference:

• direct fund transfer to our Australian accounts (please quote the invoice number in the reference or message section of the transfer form),
• Visa, MasterCard, American Express, Diners and JCB credit cards (we charge a 3.5% surcharge on credit card payments), and
• cheques.

We usually invoice services after you have received the data but we can also invoice in advance and provide quotes.