All measurements were performed in duplicate using Single Molecule Array technology (Quanterix) with the commercial NF‐Light advantage Kit and GFAP Discovery Kit on a HD‐X platform according to the manufacturer’s instructions (www.quanterix.com/products-technology/assays ). The inter-assay variation for NfL was 8%, based on three levels of internal quality control pools, measured in 45 runs. The inter-assay variation for GFAP was 15%, based on three levels of internal quality control pools, measured in 40 runs. The mean intra‐assay coefficients of variation (duplicate measurements) were <10% for both NfL and GFAP. Therefore, samples with too low volume for a duplicate measurement (n = 4) were also included in the analysis. Based on an in-house quality study, NfL values in heparin plasma, GFAP values in serum and GFAP values in heparin plasma were adjusted by −29, −13 and −18%, respectively, to allow comparison between measurements in heparin plasma, serum and EDTA plasma.31 (link),32 Finally, the GFAP values of the adult reference cohort were multiplied by a factor of 1.3, based on internal quality control values, to correct for inter-batch variability. All measurements were performed by certified technicians at the Neurochemistry laboratory of the Amsterdam UMC location VUmc blinded to clinical information.
Gfap discovery kit
Manufactured by Quanterix
Sourced in United States
The GFAP Discovery Kit is a laboratory equipment product developed by Quanterix. It is designed for the detection and quantification of Glial Fibrillary Acidic Protein (GFAP) in biological samples. The kit utilizes specialized reagents and protocols to enable researchers to measure GFAP levels accurately and reliably.
Automatically generated - may contain errors
Lab products found in correlation
Nf light advantage kit, by Quanterix (3 mentions)
Single molecule array technology, by Quanterix (1 mentions)
Serum separator tubes, by Sarstedt (1 mentions)
Simoa sr x platform, by Quanterix (1 mentions)
Lumipulse g600ii platform, by Fujirebio (1 mentions)
Nf light kit, by Quanterix (1 mentions)
Simoa technology, by Quanterix (1 mentions)
6 protocols using gfap discovery kit
1
Quantification of Neurological Biomarkers
2
Biomarkers of Neuroinflammation and Neurodegeneration in Asthma
3
Plasma GFAP Biomarker Analysis Protocol
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Venous blood samples were originally drawn from all enrolled patients, and a part of the blood was analyzed at Tampere University Hospital (Tampere, Finland) for a previous study.22 (link) The remaining serum and plasma samples were immediately frozen at −70°C for future use. Samples were sent to the Sahlgrenska University Hospital, Mölndal, Sweden (transfer in 20 kg of dry ice by a courier) for further analyses. On September 14–15, 2019, the samples were analyzed using the GFAP Discovery Kit (Quanterix, Billerica, MA) on an HD-1 Simoa instrument to determine plasma GFAP levels. The lower limit of detection and lower limit of quantification were 0.211 and 0.686 pg/mL, respectively. The laboratory technicians performing the analyses were blinded to the clinical data. The details of our GFAP analytics are described more comprehensively in a previous publication and in the Supplementary Material.25 (link)
4
Serum Biomarker Quantification Protocol
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Blood was collected into serum separator tubes (Sarstedt AG & Co). After coagulation
(for 45 ± 15 min) and centrifugation at 1500g for 10 min, the serum was
aliquoted into cryovials and stored at −80°C. Serum was transferred between centres and
laboratories on dry ice. Blood biomarkers were quantified using commercially available
single plex [NF-light™ Advantage Kit (103186); GFAP Discovery Kit (102336)] Simoa assays
according to the manufacturer’s instructions (Quanterix). The performance of the assay was
determined by internal quality control (iQC) samples. The intermediate precision and
repeatability for the high concentration iQC was <8% and <12%, respectively for both
biomarkers. The low iQC was demonstrated with an intermediate precision of 4.8% and
repeatability 11.3% for NFL. The GFAP low iQC demonstrated an intermediate precision of
3.3% and repeatability 6.7%.
(for 45 ± 15 min) and centrifugation at 1500g for 10 min, the serum was
aliquoted into cryovials and stored at −80°C. Serum was transferred between centres and
laboratories on dry ice. Blood biomarkers were quantified using commercially available
single plex [NF-light™ Advantage Kit (103186); GFAP Discovery Kit (102336)] Simoa assays
according to the manufacturer’s instructions (Quanterix). The performance of the assay was
determined by internal quality control (iQC) samples. The intermediate precision and
repeatability for the high concentration iQC was <8% and <12%, respectively for both
biomarkers. The low iQC was demonstrated with an intermediate precision of 4.8% and
repeatability 11.3% for NFL. The GFAP low iQC demonstrated an intermediate precision of
3.3% and repeatability 6.7%.
5
CSF Biomarkers in Neurodegeneration
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
CSF samples were obtained by LP at the L3/L4 or L4/L5 intervertebral level, centrifuged in case of blood contamination, divided into aliquots, and stored in polypropylene tubes at −80 °C until analysis. For the AD core biomarkers measurements, t-tau, p-tau, Aβ42, and Aβ40 were measured by automated chemiluminescent enzyme immunoassay on the Lumipulse G600II platform (Fujirebio, Gent, Belgium). The inter-assay coefficients of variation (CVs) were <8% for all biomarkers. Pathological values for defining the A/T status were determined using validated cutoff values [33 (link)]. More specifically, an Aβ42/Aβ40 ratio < 0.65 and a p-tau > 62 pg/mL supported the A+ and T+ statuses, respectively.
Commercially available ELISA kits were used to measure the NfL and 14-3-3 gamma isoform, as described [34 (link),35 (link)]. The GFAP concentrations were determined by running the commercially available GFAP Discovery Kit (Quanterix) on the SiMOA SR-X platform (Quanterix, Billerica, MA, USA). The intra-assay and the inter-assay CVs were respectively 7% and 15% for NfL, 6% and 13% for 14-3-3, and 8% for GFAP (only one plate was used). Eventually, all CSF samples from patients without autopsy examination, classified as probable sCJD or np-RPD, were tested by the second-generation prion RT-QuIC, as described [6 (link)].
Commercially available ELISA kits were used to measure the NfL and 14-3-3 gamma isoform, as described [34 (link),35 (link)]. The GFAP concentrations were determined by running the commercially available GFAP Discovery Kit (Quanterix) on the SiMOA SR-X platform (Quanterix, Billerica, MA, USA). The intra-assay and the inter-assay CVs were respectively 7% and 15% for NfL, 6% and 13% for 14-3-3, and 8% for GFAP (only one plate was used). Eventually, all CSF samples from patients without autopsy examination, classified as probable sCJD or np-RPD, were tested by the second-generation prion RT-QuIC, as described [6 (link)].
6
Biomarker Quantification in Plasma and CSF
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Blood was collected in 4‐mL EDTA tubes and processed within 2 hours at the biobank of Amsterdam UMC. Samples were centrifuged for 10 minutes at 2000g and plasma was stored at −80°C in 0.5 mL volumes until further use. CSF was collected in 10‐mL polypropylene tubes and centrifuged for 10 minutes at 1800g, supernatant was aliquoted in 0.5 mL volumes and stored at −80°C until further use.
Measurements of NfL and GFAP in plasma and CSF were performed in the Neurochemistry laboratory of the Amsterdam UMC location VUmc using the single‐molecule array (SiMoA) technology (Quanterix Corp., MA USA). Analyses were performed using the NF‐light Kit (Quanterix) and GFAP Discovery Kit (Quanterix), run on the SiMoA HD‐1 according to the manufacturer’s protocols (www.quanterix.com/products‐technology/assays ). Measurements were performed in duplicate by certified technicians that were blinded to clinical information. The average variation of duplicate measurements was 4.8% for NfL and 3.3% for GFAP.
Measurements of NfL and GFAP in plasma and CSF were performed in the Neurochemistry laboratory of the Amsterdam UMC location VUmc using the single‐molecule array (SiMoA) technology (Quanterix Corp., MA USA). Analyses were performed using the NF‐light Kit (Quanterix) and GFAP Discovery Kit (Quanterix), run on the SiMoA HD‐1 according to the manufacturer’s protocols (
About PubCompare
Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.
We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.
However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.
Ready to get started?
Sign up for free.
Registration takes 20 seconds.
Available from any computer
No download required
Revolutionizing how scientists
search and build protocols!