Lipid coating of paramagnetic microspheres reduces non-specific binding to Kelly neuroblastoma cells.
In an effort to reduce non-specific binding interactions (binding in the absence of antibody), sheep anti-mouse IgG1 (Fc) antibody linked to magnetic microspheres (also referred to as microbeads or beads) were treated with phosphatidylcholine (PC), phosphatidylglycerol (PG), or a mixture of PC and PG. The lipid-treated microspheres were mixed with Kelly neuroblastoma cells, which had been pre-labelled with Hoechst fluorochrome. After 30 minutes of incubation, the microsphere adherent cells were separated from the non-adherent cells and counted. PC or mixed lipid treatment of beads reduced nonspecific binding to 8.3%, compared to 25.8% in the untreated samples. PG, on the other hand, increased non-specific binding. Lipid treatment of beads did not adversely affect specific antibody mediated binding. When a non-specific antibody was added to the incubation mixture, non-specific binding of untreated control beads to cells was increased, but binding of PC-treated beads was unaffected.
College of Medicine, Department of Pediatrics, University of Florida, Gainesville.
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Kedar
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Schreier
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Rios
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Janssen
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Gross
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D000943:Antigens, Differentiation / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D001562:Benzimidazoles; D006801:Humans; D008280:Magnetics; D008863:Microspheres; D015260:Neprilysin; D009447:Neuroblastoma / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000494:pharmacology; D010715:Phosphatidylglycerols / Q000494:pharmacology; D013194:Staining and Labeling; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D001562:Benzimidazoles; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D015260:Neprilysin; C017807:bisbenzimide ethoxide trihydrochloride