Abstract:In this study,we aims to study the main factors such as magnetic separation time,target capture rate,specificity,sensitivity that affect the performance of immunomagnetic beads (IMB). IMB were prepared chemically and the capture rate of target bacteria were determined by plate culture counting. The target bacteria capture rate varies in different magnetic separation time,which affected the capture rate,and the capture rate of IMB would reach the highest level. The amount of magnetic balls and antibody affect the capture performance of IMB. When the Feed ratio was 200 μg of magnetic ball and 25 μg of antibody,the capture rate would get more than 50%And IMB has a sensitivity (the capture rate is above 50% on target bacteria with 100 cfu /mL).The target capture rate of IMB with the large diameter(1 000 nm)is less than that of those with the small diameter (180 nm)at the same mass. The nonspecific capture rate for Escherichia coli,Staphylococcus aureusand Shigella was below 10%,which affected the immune specificity of IMB. This study provided a foundation and some data for application of IMB and detection of microorganisms.
