Magnetic beads in suspension enable a rapid and sensitive immunodetection of human placental alkaline phosphatase.
The kinetics and efficiency of the interaction between placental alkaline phosphatase and a monoclonal antibody (laboratory number 327) were determined by immunoassay using microtitre plates or magnetic beads. While only up to 45% of placental alkaline phosphatase was bound to microwells precoated with this antibody, even after prolonged incubation, no less than 60% and 100% binding were reached using magnetic beads after 1 and 3 h incubations, respectively. High-molecular-mass placental alkaline phosphatase and complexed placental alkaline phosphatase forms were also completely bound to magnetic beads in the presence of deoxycholate (up to 9 g/l for serum samples). The assay sensitivity was improved up to 4-fold. In addition, 100% binding of the antigen was achieved during simultaneous incubation of magnetic beads, monoclonal antibody (125 micrograms/l), and placental alkaline phosphatase. This one-step enzymatic assay, based on magnetic beads, is an attractive alternative to the classic assay performed in microtitre plates, enabling rapid, precise, and sensitive antigen detection, and only necessitating a minimum of laboratory equipment.
Hendrix
P G
PG
Department Nefrologie-Hypertensie, Universitaire Instelling Antwerpen, België.
Hoylaerts
M F
MF
Nouwen
E J
EJ
Van de Voorde
A
A
De Broe
M E
ME
D000469:Alkaline Phosphatase / Q000032:analysis* / Q000097:blood; D001667:Binding, Competitive; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008280:Magnetics; D008863:Microspheres; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000469:Alkaline Phosphatase