When developing an MDx (molecular diagnostic) assay, it is vital to use the proper reference standards and controls. Reference standards, which often mimic natural biological materials, are used for developing the assay itself, whereas controls, which are often fragments of biological materials, are used to assess final working assay quality. While there are many such predesigned and tested products available to purchase, customization allows flexibility not otherwise possible. Our Custom Molecular (DNA and RNA) Reference Standards & Controls are platform independent and ideal for use with common MDx assay technologies, such as PCR and NGS.

For example, if you are developing an RT-qPCR assay for the detection and quantification of an RNA virus involved in respiratory disease, such as SARS-CoV-2, any or all of the following might be needed:

  • Reference standard – custom near-whole* genome to test the efficacy of different assays on various gene targets.
  • Exogenous (spiked) positive control – custom gene/transcript fragment to check for the presence of RT or PCR inhibitors that might be present in the sample. This type of control helps rule out false negatives.
  • Exogenous (separate) positive control – custom gene/transcript fragment to ensure the RT and PCR steps are performing optimally. This can be considered a type of functional quality control.

*Whole viral genomes are not allowed for safety reasons

Product Benefits

  • Multiple sequence orders are made one at a time to prevent cross contamination
  • Proprietary DBS buffer (excellent for nucleic acids) is available; it allows for significant dilution of nucleic acids, especially RNA, and functions as a stabilizing agent for low copy numbers
  • Consistent lot-to-lot performance

Product Features

For anything marked as ‘Inquire’ or If you have needs that are different from the other general specifications presented, please fill out the Optional Information box on the request form.

**ssDNA is available (inquire for feasibility).

Product Manufacturing

After we receive your desired sequence, manufacturing of reference standards and controls occurs via the following steps (see Figure 1 for a condensed, graphical version of dsDNA and ssRNA manufacturing):

dsDNA

1. Synthesis of the dsDNA gene or fragment
2. Cloning of the gene or fragment into a plasmid
3. Sequencing verification of the plasmid insert
4. Synthesis of plasmid-specific PCR primers
5. PCR amplification of the cloned insert
6. Purification of PCR-amplified insert via spin column
7. QC of PCR-amplified insert via capillary electrophoresis
a) End of process for dsDNA product

ssRNA

8. In vitro transcription of PCR-amplified insert
9. Removal of DNA template with DNase
10. Purification of RNA via spin column
11. Quality control of RNA via capillary electrophoresis
a) End of process for ssRNA product

dsRNA

12. Separate syntheses of sense and antisense DNA strands
13. Pooling of both strands in equimolar amounts
14. In vitro transcription and hybridization
a) End of process for dsRNA product

Following cloning of the gene or fragment, PCR is used to amplify the desired insert.

Figure 1.Following cloning of the gene or fragment, PCR is used to amplify the desired insert. Direct PCR leads to dsDNA products. IVT (in vitro transcription) of the PCR product leads to the ssRNA product.

Materials
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