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  • Author: Bjorn Larsen x
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Abstract

We examined the chemical composition of Palmaria palmata collected monthly from April 1998 to September 1999 in the Trondheimsfjord, Norway. Clear seasonal variations in ash (15–27% of dw), proteins (14–30% of dw) and the low molecular weight carbohydrate, floridoside (3.3 to 25% of dw) were observed. A new and simple method for quantification of floridoside based on extraction and dialysis is described. Ash was high during winter and spring and low during summer-autumn, and the same trend was observed for protein. The opposite trend was observed for floridoside, which showed dramatic variation from less than 5% (of dw) from January to March to more than 20% from June to August. The xylan fraction constituted 24–35% of dw. Monomer galactose and xylose were always very low. Examination of samples collected at 3-month intervals during 1998–1999 in Portaferry (Northern Ireland), Galway (Ireland) and Oviedo (Spain), in addition to Trondheim (Norway), showed geographic variations among the major constituents. A wide range of dry matter contents (10–22% of wet weight) and ash contents (17–37% of dw) was observed. Total protein was high compared to other seaweeds (maximum 30% of dw). The Portaferry samples had a peak in spring that was not observed at the other three localities, where protein levels were high during winter. The content of floridoside was highest in summer samples from Trondheim and Oviedo, while the peak occurred in autumn for the Galway samples. No peak in floridoside was observed for the Portaferry samples, probably due to a relatively high content of nitrogenous nutrients in the water at this site.

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.