Annexin V has a high affinity for phosphatidylserine (PS), which becomes exposed on the outer leaflet of cells undergoing apoptosis. Because of this affinity, fluorescently labeled annexin V reagents are commonly used in apoptosis research.

Annexin V conjugates provide quick and reliable detection methods for studying the externalization of phosphatidylserine, an indicator of intermediate stages of apoptosis. The difference in fluorescence intensity between apoptotic and nonapoptotic cells stained with our fluorescent annexin V conjugates, as measured by flow cytometry, is typically about 100-fold.

In collaboration with Nexins Research BV, we provide the best and brightest annexin V conjugates available, including Alexa Fluor 350, 488, 555, 568, 594, 647, and 680 annexin V conjugates, as well as Annexin V APC, Biotin-X, FITC, Pacific Blue, and PE conjugates. Highly fluorescent annexin V conjugates provide quick and reliable detection methods for studying the externalization of phosphatidylserine, one of the earliest indicators of apoptosis.

The Annexin V Pacific Blue conjugate is violet excitable, making it ideal for instruments with a violet laser and for multicolor experiments that include green- or red-fluorescent dyes.

The benefits of our annexin V conjugates include:
• Conjugated to Invitrogen Alexa Fluor and eFluor dyes for brighter signals
• Conjugates for all available lasers
• Available as stand-alone reagents or easy-to-use kits

Annexin V staining to detect apoptotic cells can only be done on live cells and tissue. If samples are to be fixed post-staining, there are specific conditions required to achieve transient retention of signal. These include use of an alcohol-free, aldehyde-based fixation method, use of buffers containing Ca2+ and avoidance of surfactants/detergents. For your convenience, we also offer a concentrated annexin-binding buffer that facilitates the binding of annexin V to phosphatidylserine in apoptosis assays.