Education & Certifications


  • BS, College of William & Mary, Computational & Applied Mathematics & Statistics (2019)

All Publications


  • The genetic insulator RiboJ increases expression of insulated genes JOURNAL OF BIOLOGICAL ENGINEERING Clifton, K. P., Jones, E. M., Paudel, S., Marken, J. P., Monette, C. E., Halleran, A. D., Epp, L., Saha, M. S. 2018; 12: 23

    Abstract

    A primary objective of synthetic biology is the construction of genetic circuits with behaviors that can be predicted based on the properties of the constituent genetic parts from which they are built. However a significant issue in the construction of synthetic genetic circuits is a phenomenon known as context dependence in which the behavior of a given part changes depending on the choice of adjacent or nearby parts. Interactions between parts compromise the modularity of the circuit, impeding the implementation of predictable genetic constructs. To address this issue, investigators have devised genetic insulators that prevent these unintended context-dependent interactions between neighboring parts. One of the most commonly used insulators in bacterial systems is the self-cleaving ribozyme RiboJ. Despite its utility as an insulator, there has been no systematic quantitative assessment of the effect of RiboJ on the expression level of downstream genetic parts. Here, we characterized the impact of insulation with RiboJ on expression of a reporter gene driven by a promoter from a library of 24 frequently employed constitutive promoters in an Escherichia coli model system. We show that, depending on the strength of the promoter, insulation with RiboJ increased protein abundance between twofold and tenfold and increased transcript abundance by an average of twofold. This result demonstrates that genetic insulators in E. coli can impact the expression of downstream genes, information that is essential for the design of predictable genetic circuits and constructs.

    View details for DOI 10.1186/s13036-018-0115-6

    View details for Web of Science ID 000448807400001

    View details for PubMedID 30386425

    View details for PubMedCentralID PMC6206723

  • Methods for field measurement of antibiotic concentrations: limitations and outlook FEMS MICROBIOLOGY ECOLOGY Parthasarathy, R., Monette, C. E., Bracero, S., Saha, M. S. 2018; 94 (8)

    Abstract

    The growing prevalence of antibiotic resistance poses an increasingly serious threat to human health. Although an important driver of antibiotic resistance is the continuous exposure of bacteria to sublethal concentrations of antibiotics in natural environments, antibiotic pollutants are not currently tracked globally or systematically. This limits the international capacity to address the rise of antibiotic resistance at its source. To address this lack of data, the development of methods to measure antibiotic concentrations on-site is essential. These methods, ideally, must be sensitive to sublethal concentrations of antibiotics and require minimal technical expertise. Furthermore, factors such as cost, selectivity, biosafety and the ability to multiplex must be evaluated in the context of field use. Based on these criteria, we provide a critical review of current methods in antibiotic detection and evaluate their adaptability for use on-site. We categorize these methods into microbiological assays, physical and chemical assays, immunoassays, aptasensors and whole-cell biosensors. We recommend continued development of a dipstick or microfluidics approach with a bacterial promoter-based mechanism and colorimetric output. This technique would incorporate the advantageous aspects of existing methods, maximize shelf-life and ease-of-use, and require minimal resources to implement in the field.

    View details for DOI 10.1093/femsec/fiy105

    View details for Web of Science ID 000441198800002

    View details for PubMedID 29931290