Quanterix Corp, Lexington, Mass, has launched the Simoa Neurology 4-Plex A assay (N4PA). The Simoa N4PA assay can simultaneously measure four protein biomarkers from either cerebrospinal fluid (CSF) or directly from blood samples for the study of traumatic brain injury (TBI) and other neurodegenerative conditions. The four biomarkers used on the panel include neurofilament light (NF-L), tau, glial fibrillary acidic protein (GFAP), and ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1).

Recent studies indicate that serum NF-L is a biomarker for mild TBI in amateur boxers and professional hockey players, that plasma tau is related to concussion severity and return-to-play, and that serum GFAP and UCH-L1 can detect mild to moderate TBI.1–3 The TBI endpoints development initiative has also hosted a 2017 consensus conference, where thought leaders have identified NF-L, tau, GFAP, and UCH-L1 as the top four fluid biomarkers of interest for mild TBI assessment.

Kevin Hrusovsky, Quanterix.

Kevin Hrusovsky, Quanterix.

“The Simoa N4PA panel is an essential research tool for assessing head trauma-induced neural damage, particularly mild cases of TBI, which are the hardest to detect,” says Kevin Hrusovsky, executive chairman and CEO at Quanterix. “The assay is the first of its kind to detect all four key neuro biomarkers linked to TBI. This can be done simultaneously in a single well, at 1/1000th of the concentration level required by traditional enzyme-linked immunosorbent assays. As a result of continued product advances, we plan to usher this ultrasensitive multiplex technology into the clinic, and develop the most accurate and predictive tests for neurological disorders.”

The assay’s high degree of sensitivity allows the use of blood serum or blood plasma to detect neurological biomarkers, in place of conventional CSF sampling that is invasive and painful. Similarly, the assay’s ultralow detection level makes it possible to measure the biomarkers from early/mild stages to severe impairment.

“The design of this multiplexed assay will provide researchers with the insights needed to speed the development of a new generation of diagnostic products that will hopefully be useful for early detection of neurological disease,” says Henrik Zetterberg, MD, PhD, professor of neurochemistry and head of the department of psychiatry and neurochemistry at Sahlgrenska Academy of the University of Gothenburg. “Comparing the diagnostic and prognostic utility of tau, NF-L, UCHL-1, and GFAP head-to-head in samples collected at different time points following traumatic brain injury will give us new information on how we could potentially use these markers in clinical practice.”

The assay kit includes Simoa reagents, calibrators, multiplex Simoa beads, detector antibodies, and sample diluent required to run up to 96 tests. It is available for immediate purchase to run on the Simoa HD-1 analyzer or via the Simoa Accelerator Lab, an innovation center for biomarker research, custom assay development, and clinical sample testing.

Quanterix’s research and development in the area of neurological testing, including the Simoa N4PA assay, is a result of two GE and NFL Head Health Challenge grants that have been awarded to the company since 2015. The Simoa N4PA assay is for research use only and not for use in diagnostic procedures.

For more information, visit Quanterix.


  1. Shahim P, Zetterberg H, Tegner Y, et al. Serum neurofilament light as a biomarker for mild traumatic brain injury in contact sports. Neurology. 2017;88(19):1788–1794; doi: 10.1212/WNL.0000000000003912.
  1. Gill J, Merchant-Borna K, Jeromin A, Livingston W, et al. Acute plasma tau relates to prolonged return to play after concussion. Neurology. 2017;88(6):595–602; doi: 10.1212/WNL.0000000000003587.
  1. Papa L, Brophy GM, Welch RD, et al. Time course and diagnostic accuracy of glial and neuronal blood biomarkers GFAP and UCH-L1 in a large cohort of trauma patients with and without mild traumatic brain injury. JAMA Neurol. 2016;73(5):551–560; doi: 10.1001/jamaneurol.2016.0039.