Team:UCC Ireland/Entre SeeDNA

From 2014.igem.org

Product

SeeDNA is a novel molecular diagnostic system for use in the detection of specific gene sequences. Our current proof of concept model may be used in the detection of a region of the L1 gene found on Human Papilloma Virus (HPV) 16. HPV 16 is the leading cause of cervical cancer worldwide, affecting especially poorer regions of the developing world. SeeDNA is a simple, cost effective alternative to high-tech diagnostics used in better equipped hospital labs. It does not require specialist equipment or reagents, relying only on the simple technique of transforming a circular plasmid into competent E. coli cells and growing them overnight. The principle of SeeDNA is that only plasmids which detect the target genetic sequence (approximately 50 base pairs) enters the cells to give a readout. This readout may either be in the form of cells growing on an antibiotic plate, or where instrumentation is available, a fluorescent readout. Our product could be produced as a dried DNA sample, from which hundreds of samples could be screened for a specific genetic sequence, using only simple cheap reagents found in most labs.

The majority of molecular diagnostics tests today are “home-brew” methods or “for-research-only” products offered by university, medical centres and commercial laboratories that are currently run on analytical instruments rather than purchased as a kit or reagent that carries specific diagnostic claims.

A typical SeeDNA diagnostic kit would be able to test for the presence of the genetic material of multiple pathogens

Fig. 1 The Layout of a typical SeeDNA kit.

Applications

SeeDNA could be used to detect genetic sequences in a variety of settings:

  • On the farm - SeeDNA could be used to carry out testing of animals for infection or disease. This could save money on vet costs as the farm owner themselves could carry out the test. This could be a solution also for rurally located farms where frequent testing cannot be carried out otherwise.
  • At the GP office - SeeDNA could reduce time needed to carry out molecular tests by bringing the test right to the doctor's office. Patients could be saved worry-time by getting an instant screening result from the GP at the time of sample collection.
  • In under-resourced labs - Medical laboratories, such as those in provisional hospitals run by aid workers, may lack the specialist equipment of bigger hospitals but with a low-cost, simple test such as SeeDNA, patients of these hospitals could still receive first-rate medical diagnostics.

The detection of genetic sequences is central to many lab assays, especially in the area of diagnostics.

  • Detection of Pathogenic DNA - This system could be a rapid and cheap diagnostic tool for DNA sequences from pathogenic viruses such as Human Papillomavirus (HPV), Human Immunodeficiency virus and Varicella-zoster virus (Chickenpox).
  • Variation of Digital PCR - Our system could be manipulated to mimic digital PCR, which is used to determine the amount of DNA that was in an initial sample (Hall Sedlak and Jerome, 2014). It could be used to measure how many copies of the target DNA sequence were in the original sample. A low copy number plasmid could be used in which one plasmid would be transfected into a bacterial cell. As a result one HPV16 sequence would be present in one colony. This would allow for the quantification of DNA in the original sample. Another major advantage of this would be the capability to analyze complex mixtures containing gDNA, cDNA and RNA, specifically detecting pathogenic DNA.
  • Southern Blotting - Many diseases arise by mutations in DNA that result in a faulty protein. One such disease is Sickle Cell Anaemia (SCA), which is caused by a point mutation at position 6 in the Β-globin chain of haemoglobin. This results in the aggregation of haemoglobin, which can result in the blockage of small blood vessels such as capillaries. Our detector plasmids could be tailored to detect both the normal and SCA alleles, allowing for the determination of an individual's genotype for SCA.

Limitations of current DNA Diagnostic methods:

  • Requires highly sophisticated, expensive equipment (PCR)
  • Requires expertise to use
  • Large running costs (reagents, chemicals)
  • Complicated results analysis

Advantages of SeeDNA over current diagnostics:

  • Versatility - detector plasmid can be easily changed to detect DNA sequences from any virus/bacteria.
  • No expensive equipment
  • Use of cheap reagents/chemicals
  • Straightforward, easy to use
  • Cheap/affordable
  • Rapid and efficient results
  • Requires little training to use
  • Ideal for those with limited resources

References

  • (HALL SEDLAK, R. & JEROME, K. R. 2014. The potential advantages of digital PCR for clinical virology diagnostics. Expert Rev Mol Diagn, 14, 501-7.)

Current Market Environment

Molecular diagnostics is a growing market and many laboratory tools and analytical instrument companies have set their sights on the bounty of the adjacent molecular diagnostics market, which is estimated at $2.3B in the US and is to grow at 15% CAGR over the next several years.

For analytical instrument companies, the molecular diagnostics market presents an opportunity for significant growth. Analytical instrument companies, whose core capabilities lay in the development and distribution of analytical technologies (e.g. instruments and systems), now see an opportunity to leverage their deep scientific knowledge in an adjacent market.

So far, most analytical instrument companies have entered the molecular diagnostics market through alliances and acquisitions. Specifically, companies such as Luminex and Affymetrix have invested in multiple alliances with diagnostics companies, clinical labs, as well as BioPharma for testing, validation, development and distribution of diagnostics as well as sales and marketing. These companies owe their historic success to the strong customer relationships they have been able to forge with a few large-account research and development organizations, either academic or commercial.