Immunoprecipitation (IP) is a method to pull down a protein out of solution using an antibody that specifically binds to that particular protein. Immunoprecipitation is a powerful technique to isolate and concentrate a particular protein from a sample containing many thousands of different proteins, to test protein-protein interactions, and to pull multiple members of a complex out of solution by latching onto one member with an antibody. This protocol describes a general immunoprecipitation strategy using cell cultures as starting material.

In this protocol, different types of adherent cells are fixed to coverslips by 4% paraformaldehyde. Target proteins are then stained by specific antibodies and fluorescent 2nd antibodies. This protocol therefore provides a method for immunostaining of adherent cells.

Bone marrow derived macrophages are a type of white blood cell that can be isolated from mammalian bone marrow. In this protocol, a method is described in which bone marrow cells are isolated from mouse leg bones (femur and tibia), and then differentiated to bone marrow-derived macrophages in approximately 10-day culture using L929-conditioned medium.