BAX/BAK Independent Cell Death Figure 4. BH3 Peptides do not induce release of cytochrome c from Bax2/2/Bak2/2 isolated mitochondria or MEFs. (A) Isolated mitochondria of wild type and Bax2/2/Bak2/2 MEFs were treated with BID BH3 peptide (100 mM) or mutant BID BH3 peptide (100 mM). Cytochrome c released from isolated mitochondria was determined by ELISA read at 450 nm with wavelength correction at 540 nm. Mean values6SEMs of 3 independent experiments are shown. (B and C) Wild type MEFs and Bax2/2/Bak2/2 MEFs respectively were stably transfected with cytochrome c tagged with GFP and time lapse microscopy was performed to assess for cytochrome c release upon treatment with BID BH3 peptide (100 mM), mutant BID BH3 peptide (100 mM) or BIM BH3 peptide (80 mM) Pictures were taken prior to peptide treatment and at 1 minute intervals post peptide treatment. doi:10.1371/journal.pone.0005646.g004 PLoS ONE | www.plosone.org 6 May 2009 | Volume 4 | Issue 5 | e5646