The Positive Control (PC) is a genotype predicted to score for the majority of the markers in the panel and is required to be submitted with the validation service (or prior if preferred).

The PC is used internally for DArTag assay QC purposes, with one PC for every 94 samples processed. For panels predicted to be used for thousands of samples, it is important to select the genotype which can be resubmitted as required.

The Positive Control (PC) can be submitted either as already extracted gDNA or as tissue for extraction to be processed by DArT.

PC submitted as gDNA

We require a minimum of 500 µl of 50–100 ng/µl High Molecular Weight (HMW) and pure gDNA with quality suitable for DNA-modifying enzymes. If the panel is predicted to be used for thousands of samples, proportionally larger quantities of gDNA PC are required.

gDNA PC can be submitted suspended in TE buffer, precipitated, or lyophilised. Any molecular-grade plastic container of suitable size may be used.

The completed PC Specification Document – gDNA has to be included in the shipment alongside all other required documentation if shipped from overseas.

PC Specification Document gDNA links the physical PC sample with the correct product and provides technical details on quantity.

PC submitted as tissue

The tissue quantity depends on the predicted number of samples to be processed on the panel. A few grams of tissue are required for DArT’s extraction process to provide sufficient PC in most use cases.

Sample preparation and shipment depend on the organism and tissue type. Recommendations are available at:

• Plants, leaves, and seeds
• Samples from animals

The completed PC Specification Document – Tissue has to be included in the shipment alongside all other required documentation if shipped from overseas.

PC Specification Document Tissue links the physical PC sample with the correct product and provides technical details on quantity.

The validation service is a user-selected set of samples used to assess marker performance. Ordering the validation service and any follow-up services requires providing the product custom code.

Ordering details will be provided to the specified contact via email.

A minimum of 94 samples is required for panel validation; however, we recommend four plates with 94 samples. For use cases with fewer than 94 samples or more than four plates of 94 samples, please contact dart@diversityarrays.com.

When preparing the shipment of material for product validation for DArTag products, please follow our recommendations specific to Targeted Genotyping (TG) services in addition to the general sample submission recommendations.

These details are available on our website:

• General recommendations:
  https://help.diversityarrays.com/
• Targeted Genotyping (TG) service recommendations:
  https://www.diversityarrays.com/services/targeted-genotying/
  https://help.diversityarrays.com/docs/targeted-genotyping