Protein for Rapid, Efficient Capture of Tuberculosis Antigens from Urine

Applications

This technology is a paper-based diagnostic that identifies patients infected with tuberculosis

Problem Addressed

Tuberculosis (TB) is one of the top ten causes of death worldwide. TB can remain latent for years, and early stages of active disease can remain mild for months making diagnosis challenging. Additionally, TB is most common in third world countries that lack the healthcare systems to support costly specialized testing equipment. The only tests available in these countries require days to confirm a positive TB diagnosis, and many patients never receive a diagnosis because the health center is too far away to make a return trip. Therefore, there is a desperate need to develop rapid, cheap diagnostics to identify patients with TB.

Technology

This invention uses a paper-based immunoassay to identify TB. Capturing dilute target molecules remains a challenge in engineering diagnostic immunoassays. One way to overcome this challenge is to use a great excess of binding molecule to create pseudo first-order reaction conditions that can then efficiently capture nearly all target molecules in a sample. These inventors developed a bifunctional protein containing a domain to bind the urine TB biomarker Rv1656 and another domain that tightly binds cellulose. The cellulose-binding domain is used to anchor a high concentration of the bifunctional protein onto paper and the paper bound protein can capture nearly all Rv1656 from a dilute solution. Importantly, this protein can be rapidly produced and purified using bacterial culture systems.

Advantages

  • Cheap, rapid paper-based diagnostic for TB urine biomarker Rv1656
  • Efficient target capture and very low background binding gives high signal to noise ratio
  • Diagnostic application does not require specialized equipment or technical knowledge
  • Very cheap production using scalable bacterial culture and simple purification