Annexin V Kits: For Apoptosis Detection

Apoptosis, or programmed cell death, is an essential process by which multi-cellular organisms ensure that critically damaged or mutated cells are removed.

Fig. 1. Jurkat cells were treated with 1 uM for 4 hours to induce apoptosis and stained with Annexin V:SBV515 Kit (ANNEXINSBV515) and ReadiDrop propidium Iodide (1351101).

Fig. 1. Jurkat cells were treated with 1 uM for 4 hours to induce apoptosis and stained with Annexin V:SBV515 Kit (ANNEXINSBV515) and ReadiDrop propidium Iodide (1351101). 

The process is regulated by a complex interplay of proteins and, until reaching “the point of no return”, can be halted or reversed at any point.

Early apoptotic cells can be detected with the help of annexin V; a protein encoded by the ANXA5 gene, which acts as an anticoagulant. Annexin V, like other members of the annexin protein family, binds to specific membrane proteins. During the early stages of apoptosis, the plasma membrane is rearranged, which results in changes to the cell membrane’s phospholipid asymmetry. One of the effects of these rearrangements is the display of phosphatidylserine (PS) at the outer plasma membrane. In healthy, quiescent cells PS is exclusively located at the inner membrane and therefore the exposure of PS is an indication of early apoptosis (Fadeel and Xue, 2009). Annexin V has a high binding affinity for PS in the presence of Ca2+ and is therefore a common tool for detecting apoptotic cells.

When annexin V staining is combined with a viability dye, apoptotic cells can be distinguished from healthy and necrotic cells (Figure 1).


Annexin V Kit Benefits

  • Offered in a range of formats and sizes, ranging from 50 tests sizes to a 200 test size for frequent users
  • For use in multicolor flow cytometry experiments, conjugated to StarBright Dyes, PE, and APC
  • Options available for use across all five common lasers
  • StarBright Dye Annexin V conjugates spectral properties avoid excitation and emission of common viability dyes, such as 7-AAD and propidium iodide, and fluorescent proteins simplifying compensation, see tables 1-3 and Figure 2
  • PE and APC kits include the viability dye propidium iodide to enable distinction between apoptotic and necrotic cells
  • Annexin V staining buffer included with every conjugate

Labeled annexin V, included in the kits, has been conjugated such that the native phospholipid binding properties of annexin V remain unaltered.

Tables 1-3. Excitation and emission max of StarBright Dye Annexin V conjugates, common viability dyes, and fluorescent proteins.

StarBright Dyes

 

Laser

Ex max

Em max

ZE5 Filter

SBUV400

355

335

394

387/11

SBUV795

355

340

792

750LP

SBV440

405

383

436

440/22

SBV515

405

402

516

525/50

SBV790

405

402

782

750LP

SBB675

488

476

675

692/80

SBB765

488

476

764

750LP

SBY800

561

549

788

750LP

Common Non Fixable Viability Dyes

 

Laser

Ex max

Em max

ZE5 Filter

DAPI

355

359

461

460/22

PI

488

535

617

615/25

7-AAD

561

546

647

670/30

DRAQ7

640

600

697

720/60

Common Fluorescent Proteins

 

Laser

Ex max

Em max

ZE5 Filter

eCFP

405

458

480

460/22

eGFP

488

488

507

525/35

eYFP

488

515

528

525/35

mCherry

561

587

610

615/24

RFP

640

674

703

720/60

Fig. 2. Emission profiles of Annexin V conjugates


Fig. 2. Emission profiles of annexin V conjugates. Emission profiles split by excitation laser for annexin V conjugates, common viability dyes, and common fluorescent proteins. Filters used on the ZE5 Cell Analyzer are also shown to highlight the differences in max emission for the annexin V conjugates which facilitate their use in multicolor panels with reduced spillover and spreading.

Our Annexin V Kit Range

    DescriptionSpecificityTargetFormatHostIsotypeClone Applications Citations Product Type Code Validation Types


    Reference