Mal-PEG4-NHS ester The experimental goal is to conjugate an IgM antibody (total molecular weight 144.7 kDa) to a single-stranded DNA (20-30 kDa), which has a thiol group at one end, using this linker. The molar ratio of the linker to antibody added was 80:1. The conjugation was verified by polyacrylamide gel electrophoresis, but there were some issues with the results. I would like to consult:

The ratios 1:7, 1:3, 1:1, 1:0.5 are the antibody-to-DNA ratios. MG7 group: Antibody only, no linker or DNA. Activated group: MG7 antibody with linker added, but no DNA. DNA group: DNA only.

Result analysis: In the lanes where the linker and/or DNA were added, the bands migrated much higher, indicating a very large molecular weight. Furthermore, the heavy and light chains could not be distinguished. I suspect if the antibodies cross-linked with each other? It's unclear if the DNA was successfully conjugated. Expected result: The heavy and light chains should be distinguishable, with bands corresponding to antibodies conjugated to different numbers of DNA molecules.