A homogeneous immunoassay for detection of the interaction between two tumor biomarkers of IGF1R‐β and SOCS1

The current protein interaction method is time consuming and cumbersome or the instrument is expensive. A new method that is convenient, fast, and high throughput needs to be studied urgently. The purpose of this study was to establish a homogeneous immunoassay to detect the interaction between insulin‐like growth factor‐1 receptor‐β (IGF1R‐β) and suppressor of cytokine signaling 1 (SOCS1). The recombinant vectors IGF1R‐β/pENTER and SOCS1/pENTER were constructed and transfected into 293T cells. Based on homogeneous immunoassay technology, we established a suitable method. The signal intensity in the 293T lysate that overexpressed IGF1R‐β and SOCS1, respectively, was compared with the signal intensity in the simultaneous expression of IGF1R‐β and SOCS1. The interaction between IGF1R‐β and SOCS1 was verified in vitro. The detection system for the interaction between IGF1R‐β and SOCS1 was established. Compared with other methods, homogeneous immunoassay has the advantages of being rapid and sensitive, having higher sensitivity, and easy to operate. The interaction between IGF1R‐β and SOCS1 was tested to verify the feasibility of this method and prove its practicability and sensitivity. This new method can be used as a high‐throughput platform for protein–protein interaction, with the advantages of trace detection, short detective time, and high detective sensitivity. Schematic representation of the homogeneous immunoassay. Donor beads that are directly conjugated to anti‐IGF1R‐β antibodies capture the IGF1R‐β. Acceptor beads that are directly conjugated to anti‐SOCS1 antibodies capture the SOCS1. Acceptor beads coated donor beads capture the immune complex between IGF1R‐β and SOCS1, bringing donor beads into close proximity to the acceptor beads. After excitation at 680nm, acceptor beads receive singlet oxygen from donor beads and produce fluorescent emission range from 520 to 620nm. As shown in the lower image, if no interaction between IGF1R‐β and SOCS1, the distance would be greater than 200 nm, resulting in no emission.