To cite testassay in publications use:

Fay, M. P., Sachs, M. C., & Miura, K. (2018). Measuring precision in bioassays: Rethinking assay validation. Statistics in medicine, 37(4), 519-529.

Corresponding BibTeX entry:

  @Article{,
    title = {Measuring precision in bioassays: Rethinking assay
      validation},
    author = {{Fay} and M. P. and {Sachs} and M. C. and {Miura} and
      {K.}},
    journal = {Statistics in Medicine},
    year = {2018},
    volume = {37},
    number = {4},
    pages = {519--529},
    url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5771887/},
  }