細胞凋亡是胚胎發(fā)育和維持組織穩(wěn)態(tài)的正常生理過程。凋亡過程具有一定的形態(tài)學特征，包括質(zhì)膜不對稱和附著的喪失、細胞質(zhì)和細胞核的凝聚以及核小體間DNA的分裂。質(zhì)膜的丟失是最早的特征之一。在凋亡細胞中，細胞膜磷脂磷脂酰絲氨酸(PS)從質(zhì)膜的內(nèi)葉轉(zhuǎn)移到外葉，從而使PS暴露于細胞外環(huán)境。膜聯(lián)蛋白V是一種35-36 kDa的Ca2+依賴性磷脂結合蛋白，對PS具有高親和力，并與暴露PS的細胞結合。膜聯(lián)蛋白V可以偶聯(lián)到包括FITC在內(nèi)的熒光染料上。這種格式保留了對PS的高親和力，因此可以作為流式細胞術分析細胞凋亡的敏感探針。由于PS外化發(fā)生在細胞凋亡的早期階段，因此FITC Annexin V染色比基于細胞核變化(如DNA斷裂)的檢測更能識別細胞凋亡的早期階段。

Apoptosis is a normal physiologic process which occurs during embryonic development as well as in maintenence of tissue homeostasis. The apoptotic program is characterized by certain morphologic features, including loss of plasma membrane asymmetry and attachment, condensation of the cytoplasm and nucleus, and internucleosomal cleavage of DNA. Loss of plasma membrane is one of the earliest features. In apoptotic cells, the membrane phospholipid phosphatidylserine (PS) is translocated from the inner to the outer leaflet of the plasma membrane, thereby exposing PS to the external cellular environment. Annexin V is a 35-36 kDa Ca2+ dependent phospholipid-binding protein that has a high affinity for PS, and binds to cells with exposed PS. Annexin V may be conjugated to fluorochromes including FITC. This format retains its high affinity for PS and thus serves as a sensitive probe for flow cytometric analysis of cells that are undergoing apoptosis. Since externalization of PS occurs in the earlier stages of apoptosis, FITC Annexin V staining can identify apoptosis at an earlier stage than assays based on nuclear changes such as DNA fragmentation.

Components

Part ? No.

Description

Size

51-65874X

FITC ? Annexin V

0.5 ? mL (1 ea)

51-66211E

Propidium ? Iodide Staining Solution

2 ? mL (1 ea)

51-66121E

10X ? Annexin V Binding Buffer

50 ? mL (1 ea)

PREPARATION AND STORAGE

Store undiluted at 4°C and protected from prolonged exposure to light. Do not freeze.

PRODUCT NOTICES

1.Since applications vary, each investigator should titrate the reagent to obtain optimal results.

2.Source of all serum proteins is from USDA inspected abattoirs located in the United States.

3.Caution: Sodium azide yields highly toxic hydrazoic acid under acidic conditions. Dilute azide compounds in running water before discarding to avoid accumulation of potentially explosive deposits in plumbing.

4.Please refer to www.bdbiosciences.com/pharmingen/protocols for technical protocols.