Bio-Rad Bio-Plex Pro™ Human Chemokine Assays - Manual (Page 3)

Introduction
Chemokines are small molecular weight (8–10 kD) cytokines secreted by
various eukaryotic cell types, including those of the immune system. Their
main function is to promote and regulate cell migration in both normal
and pathological conditions, including immune surveillance, inflammation,
angiogenesis, microbial infection, autoimmune diseases, tumor growth,
vascular diseases, and transplant rejection (Locati et al. 2005, Slettenaar
and Wilson 2006). The regulatory functions of chemokines are exerted
via binding and signaling through specific G protein–coupled receptors
expressed on the surface of chemokine-responsive cells.
Chemokines are classified into four subfamilies (C, CC, CXC, and CX3C)
based on the number and spacing of cysteine residues within the protein
sequence. The C chemokines are known as lymphotactins, and are
found at high levels in spleen, thymus, intestine, and peripheral blood
leukocytes. The CC chemokines have the first two cysteines in adjacent
positions and are known to attract granulocytes and lymphocytes,
including NK cells. The CXC chemokines have the first two of four
cysteines separated by a single amino acid, denoted X. Most CXC
chemokines are chemo-attractants for neutrophils and lymphocytes. The
CX3C chemokines have three amino acids inserted between the first two
cysteines. The only CX3C chemokine discovered to date is fractalkine,
which is both a chemo-attractant and adhesion molecule.
Multiplexing with Bio-Plex Pro Chemokine Assays
Bio-Plex Pro chemokine assays enable researchers to quantify multiple
protein biomarkers in a single well of a 96-well plate in just 3–4 hours.
These robust immunoassays require as little as 12.5 μl of serum or
plasma or 50 μl of other biological fluid. The use of magnetic (MagPlex)
beads allows researchers to automate wash steps on a Bio-Plex Pro
(or similar) wash station. Magnetic separation offers greater convenience
and reproducibility compared to vacuum filtration.
For more information please visit www.bio-rad.com/bio-plex.
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