Isolation and Characterization of Non-Hematopoietic Cells

Cells were isolated from the bone marrow, spleen, lymph nodes, and lung as previously described [11 , 22 , 23 (link)]. After hypotonic lysis to remove erythrocytes, single cell suspensions were prepared. CD45^negative (non-hematopoietic cells) were isolated from the lung. To do so, 1% low melting point agarose was inserted into the lung via the trachea, and the tissue was then digested with dispase. CD45^negative cells were isolated from the resulting cell suspension using a magnetic enrichment beads conjugated to an anti-mouse CD45 antibody (Miltenyi Biotec, Auburn, CA). Genomic DNA was isolated from cell suspensions using a QIAamp DNA Mini Kit (QIAGEN), and PCR to detect the excised Ahr allele was performed as previously described [20 (link), 23 (link), 24 (link)].