Co-IP of BAX and BAK by anti-rabbit IgG VHH agarose (rIGa) using a BAX polyclonal IgG (Proteintech: 50599-2-Ig). As control an IgG isotype control antibody (Proteintech: 98136-1-RR) was used (BISO). 5 µg of each IgG was spiked into HEK293T cell lysate derived from 0.5x10^7 cells. 1% of input (IN) and flow through (FT) and 25% of bound (B) fraction was loaded onto an SDS-PAGE gel. For Western blot analysis BAX was detected using a polyclonal rabbit IgG (Proteintech: 50599-2-Ig) (1:2000) labeled using FlexAble HRP (Proteintech: KFA005). The presence of BAK co-precipitated with BAX was confirmed using a polyclonal rabbit IgG (Proteintech: 29552-1-AP) (1:2000). While rIGa allows for clean detection of both proteins, Protein A agarose show additional bands, probably due to leaching of Protein A from the beads into the IP fractions, which can lead to binding of the detection antibody and unspecific signals.

Co-IP of MCM complex via pulldown of MCM6 using 5 µg of polyclonal rabbit anti-MCM6 antibody (Proteintech: 13347-2-AP) and anti-rabbit IgG VHH agarose (rIGa). All subunits of the 600 kDa hetero-hexameric complex are successfully precipitated, as shown in a Coomassie blue stained SDS-gel and by Western blot analysis using subunit specific antibodies. Apparent molecular weights are provided. For input (IN) and flowthrough (FT) fractions, 1% was loaded, respectively. For bound (B) fraction and bound fraction of isotype control antibody (BISO Proteintech: 98136-1-RR), 20% was loaded. Product codes for Proteintech antibodies are provided in parentheses.