title: Validation of a new assay for α-synuclein detection in cerebrospinal fluid.
abstract: BACKGROUND
  Abnormal α-synuclein aggregation and deposition is the pathological hallmark of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), but is also found in Alzheimer disease (AD). Therefore, there is a gaining interest in α-synuclein in cerebrospinal fluid (CSF) as potential biomarker for these neurodegenerative diseases. To broaden the available choices of α-synuclein measurement in CSF, we developed and validated a new assay for detecting total α-synuclein.
  
  
  METHODS
  This novel ELISA uses commercially available antibodies and is based on electrochemiluminescence technology. The assay protocol is straightforward, with short and simple incubation steps, and requires only small amounts of CSF. We validated this assay for precision, parallelism, dilution linearity, specificity, and spike recovery. We further compared it to the newly validated α-synuclein assay from BioLegend by analyzing a set of 50 CSF samples with both assays.
  
  
  RESULTS
  The new assay quantifies α-synuclein in CSF with a lower limit of detection of 36.3 pg/mL and shows no cross-reactivity with human β- and γ-synuclein. Results of dilution linearity, parallelism, spike recovery, and precision classify this assay as well suited for α-synuclein detection in human CSF samples.
  
  
  CONCLUSIONS
  We present a novel assay based on freely available components to quantify total α-synuclein in CSF as an additional method for α-synuclein as a biomarker in neurodegenerative diseases. The assay convinces with its simple and convenient protocol paired with high sensitivity.
authors.forename: Marthe Gurine
authors.initials: MG
authors.lastname: Førland
authors.forename: Annika
authors.initials: A
authors.lastname: Öhrfelt
authors.forename: Linn Silje
authors.initials: LS
authors.lastname: Oftedal
authors.forename: Ole-Bjørn
authors.initials: OB
authors.lastname: Tysnes
authors.forename: Jan Petter
authors.initials: JP
authors.lastname: Larsen
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.forename: Guido
authors.initials: G
authors.lastname: Alves
authors.forename: Johannes
authors.identifier: http://orcid.org/0000-0003-0604-4891
authors.initials: J
authors.lastname: Lange
mesh_terms: D015415:Biomarkers / Q000032:analysis; D055664:Electrochemical Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008163:Luminescent Measurements; D051844:alpha-Synuclein / Q000134:cerebrospinal fluid*
chemical_list: D015415:Biomarkers; D051844:alpha-Synuclein