Measurement of nine human milk proteins by nephelometric immunoassays: application to the determination of mature milk protein profile.
OBJECTIVE
Microparticle-enhanced nephelometric immunoassays for six human milk proteins (beta-casein, kappa-casein, alpha-lactalbumin, serum albumin, lactoferrin, and lysozyme) and conventional immunonephelometry assays for immunoglobulin A, C3, and C4 complement proteins were developed and characterized.


METHODS
Microparticle-enhanced nephelometric immunoassays are competitive assays based on the nephelometric quantification of the inhibition of microparticle-protein conjugates immunoagglutination by the proteins to be assayed.


RESULTS
High precision (CVs ranged from 1% to 14% in within- and between-assays) and recovery (linear recovery in dilution-overloading assay) ensure a reliable determination of the main human milk proteins by single-step homogeneous nephelometric immunoassays, accurate over wide ranges of concentration. These immunoassays were easily applied to a large number of mature human milk samples (between 373 and 503 according to the proteins tested).


CONCLUSIONS
The immunoassays developed could be applied to the fast determination of human milk protein profile usable for nursery milk bank and fortification.
GRIP, Immunology Laboratory, Faculty of Medicine, Nancy, France. paulmont@grip.u-nancy.fr
P M
PM
Montagne
V S
VS
Trégoat
M L
ML
Cuillière
M C
MC
Béné
G C
GC
Faure
D002138:Calibration; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008894:Milk Proteins / Q000032:analysis* / Q000276:immunology; D008895:Milk, Human / Q000737:chemistry*; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D012016:Reference Values
D008894:Milk Proteins