Apoptosis Detection Methods

Apoptosis can be detected by a number of different methods, each of which has advantages and disadvantages. Best practice dictates that more than one method should be used to verify an apoptotic event.

Find out about key apoptotic events

• Phosphatidylserine Externalization
• Mitochondrial Changes in Apoptosis
• Caspase Cleavage and Activation
• DNA Fragmentation

General Sequence of Apoptotic Progression

Timeline for Observing Apoptotic Events

Apoptosis is a dynamic process and determining the optimal time to measure the incidence of apoptosis or the activity of the molecules involved is critical for understanding the underlying mechanisms. Several factors can influence the timing, including cell type, apoptotic stimulus, the specific apoptotic mechanism involved, and experimental conditions. Thus, the design of early experiments should factor in a time course, when replicating previously published results.

Apoptotic Mechanisms May Vary with Cell Types

Several factors can affect how cells respond to an apoptosis-inducing agent and so it is important to understand the biological system under study. For example, primary cells may respond to death stimuli differently compared to immortalized cells. Likewise, cancer cell lines may respond differently from primary tumors, or freshly explanted cells, if only because these cells may have unique sets of genetic alterations that result in the activation of oncogenes or the inactivation of tumor suppressor genes impacting apoptosis. For instance, the human breast adenocarcinoma cell line, MCF-7, lacks Caspase 3, while primary neurons do not express Bak, depending almost exclusively on Bax for mitochondria-mediated apoptosis.

View Protocols of Apoptosis Detection Methods