BIOXYTECHÒ Lactoƒ EIA™

Human lactoferrin (LTF) is an 80 kDa glycoprotein which was first isolated from human milk. LTF is found
in most body fluids and secretions, e.g., in the nose, genital tract, and tears.1
In the blood, LTF is
secreted by neutrophils and its plasma concentration is positively related to the total pool of neutrophils
and to the rate of neutrophil turnover.2
Because of its ability to strongly bind iron, LTF is considered to be
bactericidal.3
In a number of cases of inflammation, LTF is released into the extracellular medium from
secondary granules of neutrophilic leukocytes.4,5 Its extracellular concentration can therefore be used as
an index of neutrophil activation, especially in blood samples containing anti-myeloperoxidase antibodies.
Principle of the Procedure
The BIOXYTECH®
Lactoƒ-EIA™ method is an enzyme-linked immunosorbent assay (ELISA). Lactoferrin
is captured by a monoclonal antibody (MAb) that is coated on wells of a sectional microplate. A second
LTF-MAb labeled with biotin is added to the well and binds with the captured LTF forming a “sandwich.” A
solution of streptavidin-peroxidase is then added. Streptavidin has a high affinity for biotin and once
bound, its horseradish peroxidase (HRP) label is available for color development by addition of the
substrate, o-phenylenediamine (OPD). This color development at 450 nm is proportional to the quantity of
LTF in the sample.