Cell separations using targeted monoclonal antibodies against overproduced surface proteins

Area of Science:

• Biotechnology
• Immunology
• Microbiology

Background:

• Escherichia coli (E. coli) type 1 pili are crucial for bacterial adhesion and infection.
• Developing efficient methods for capturing E. coli is important for diagnostics and control.

Purpose of the Study:

• To quantify the binding capacity of polystyrene microspheres coated with antibodies against E. coli type 1 pili.
• To determine the surface density of immobilized antibodies and the maximum cell binding capacity of the microspheres.

Main Methods:

• Immobilization of purified monoclonal antibodies against E. coli type 1 pili onto polystyrene microspheres.
• Measurement of antibody surface density using quantitative methods.
• Incubation of antibody-coated microspheres with piliating E. coli cells at varying ratios.
• Quantification of bound E. coli cells per microsphere.

Main Results:

• A high concentration of antibody solution resulted in an antibody immobilization of 2.6 ± 0.4 mg/m².
• Antibody-coated microspheres bound a maximum of 290 ± 50 E. coli cells per microsphere.
• The maximum binding capacity was determined to be 2.9 ± 0.7 x 10^10 cells/m² of surface area.

Conclusions:

• Polystyrene microspheres functionalized with anti-E. coli type 1 pilus antibodies demonstrate a high binding capacity for these bacteria.
• This method shows potential for applications in E. coli detection and capture.