Olink

Olink®
Part of Thermo Fisher Scientific

NEUROLOGY

Gene
EFNA4

Uniprot
P52798

Protein
Ephrin-A4

See alternative names EPH-related receptor tyrosine kinase ligand 4

Uniprot Function Description

Cell surface GPI-bound ligand for Eph receptors, a family of receptor tyrosine kinases which are crucial for migration, repulsion and adhesion during neuronal, vascular and epithelial development. Binds promiscuously Eph receptors residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. May play a role in the interaction between activated B-lymphocytes and dendritic cells in tonsils.

Sample type

Human EDTA plasma and serum are the recommended sample types. Human citrate plasma and heparin plasma are also accepted. For other samples types e.g cerebrospinal fluid, (CSF), tissue or cell lysates please we recommend Olink Target 96 panels. Please note that protein expression levels are expected to vary in different sample types and certain assays may be affected by interfering substances such as hemolysate.

Precision

Precision (repeatability) is calculated from linearized NPX values over LOD.

Within run precision Coefficient of Variation (CV)
7%
Between run precision Coefficient of Variation (CV)
5%

Analytical measuring range

The technical data reported below refers to the measured value in the in vitro validation assays run using known concentrations of recombinant antigen. Please note that these figures are for reference only and CANNOT be used to convert NPX values to absolute concentrations for proteins measured in plasma or serum samples.

LOD (pg/mL)
6.1
LLOQ (pg/mL)
6.1
ULOQ (pg/mL)
3125
Hook (pg/mL)
12500
Range (logs)
2.7

Dilution factor

For optimal assay readout, Olink Explore is run using different dilutions of the original samples (undiluted, 1:10, 1:100 or 1:1000). The dilution factor for this assay is noted below and should be taken into account when estimating the appropriate addressable biological concentration of the protein based on the in vitro validation data.

Dilution factor
1:1

Sensitivity plot

The calibrator curve shown below visualizes the analytical measuring range data based on in vitro measurement of recombinant antigen. Please note that this is shown for reference only and CANNOT be used to convert NPX values to absolute concentrations for proteins measured in plasma or serum samples. The vertical dotted lines represent LLOQ and ULOQ respectively, and the horizontal line indicates the LOD.

10⁻⁵10⁻⁴10⁻³10⁻²10⁻¹10⁰10¹10²10³10⁴10⁵10⁶121086420−2−4−6pg/mLNPXReplicate4PLLODLLOQULOQ

Sample distribution plot

The plot below shows the levels of protein measured in a number of commercial plasma samples. Healthy subjects are shown in blue and samples obtained from patients with a range of diseases are shown in red. The latter include inflammatory, cardiovascular, autoimmune & neurological diseases, as well as cancer. The data is shown to give a general idea of the sort of data range to expect, but cannot cover all potential levels that may be seen in clinical samples.

121086420−2−4−6NPXControl SamplesDisease Samples