FACS Cell Sorting Cell Isolation 1 FACS fluorescenceactivated

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FACS & Cell Sorting Cell Isolation 1 - FACS (fluorescence-activated cell sorter) 2. By

FACS & Cell Sorting Cell Isolation 1 - FACS (fluorescence-activated cell sorter) 2. By density gradient: Ficoll-Hypaque, Percolletc 3 - By antibody-based methods other than magnetic beads & FAC 4 - Bymagnetic beads

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NECROSIS A APOPTOSIS B C

NECROSIS A APOPTOSIS B C

Thio proteases

Thio proteases

Detection of Apoptosis by Flow Cytometry o Early stage o Mid stage o Late

Detection of Apoptosis by Flow Cytometry o Early stage o Mid stage o Late stage Annexin V/7 -AAD(PI) TUNEL assay < Go/G 1 DNA content

B C A Apoptosis F D E

B C A Apoptosis F D E

Annexin V: An Early Marker of Apoptosis One of the earliest indications of apoptosis

Annexin V: An Early Marker of Apoptosis One of the earliest indications of apoptosis is the translocation of the membrane phospholipid phosphatidylserine (PS) from the inner to the outer leaflet of the plasma membrane. Once exposed to the extracellular environment, binding sites on PS become available for Annexin V, a 35 -36 k. Da, Ca 2+-dependent, phospholipid binding protein with a high affinity for PS.

Annexin V The translocation of PS precedes other apoptotic processes such as loss of

Annexin V The translocation of PS precedes other apoptotic processes such as loss of plasma membrane integrity, DNA fragmentation, and chromatin condensation. As such, Annexin V can be conjugated to biotin or to a fluorochrome such as FITC, PE, APC, Cy 5, or Cy 5. 5, and used for the easy, flow cytometric identification of cells in the early stages of apoptosis.

Annexin V Because PS translocation also occurs during necrosis, Annexin V is not an

Annexin V Because PS translocation also occurs during necrosis, Annexin V is not an absolute marker of apoptosis. Therefore, it is often used in conjunction with vital dyes such as 7 -amino-actinomysin (7 -AAD) or propidium iodide (PI), which bind to nucleic acids, but can only penetrate the plasma membrane when membrane integrity is breached, as occurs in the later stages of apoptosis or in necrosis.

Annexin V No Apoptosis = Cell Viability Cells that are negative for both Annexin

Annexin V No Apoptosis = Cell Viability Cells that are negative for both Annexin V and the vital dye have no indications of apoptosis: PS translocation has not occurred and the plasma membrane is still intact. Early Apoptosis Cells that are Annexin V-positive and vital dye-negative, however, are in early apoptosis as PS translocation has occurred, yet the plasma membrane is still intact.

Annexin V Late Apoptosis or Cell Death Cells that are positive for both Annexin

Annexin V Late Apoptosis or Cell Death Cells that are positive for both Annexin V and the vital dye are either in the late stages of apoptosis or are already dead, as PS translocation has occurred and the loss of plasma membrane integrity is observed. When measured over time, Annexin V and a vital dye can be used to monitor the progression of apoptosis: from cell viability, to early-stage apoptosis, and finally to late-stage apoptosis and cell death.

4. 72 93. 82 56. 69 41. 84 1. 46 2. 37 12. 67

4. 72 93. 82 56. 69 41. 84 1. 46 2. 37 12. 67 61. 22 37. 02 85. 25 2. 08 1. 76

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Group of cysteinyl-aspartic acid proteases is called caspases. Caspases have been divided into three

Group of cysteinyl-aspartic acid proteases is called caspases. Caspases have been divided into three groups based on the four amino acids aminoterminal to their cleavage site Asp-Glu-Val-Asp 3/8/2021 DEVD 16

o to 7 -amino-4 -trifluoromethyl coumarin 3/8/2021 17

o to 7 -amino-4 -trifluoromethyl coumarin 3/8/2021 17

offers an anti-PARP-FITC conjugated Cleavage Site-Specific Antibody (CSSA) that can detect apoptotic cells by

offers an anti-PARP-FITC conjugated Cleavage Site-Specific Antibody (CSSA) that can detect apoptotic cells by flow cytometry. 3/8/2021 Dr Atef Masad 18

Exogenous Terminal deoxynucleotidyl transferase (Td. T )is used to catalyze a template-independent addition of

Exogenous Terminal deoxynucleotidyl transferase (Td. T )is used to catalyze a template-independent addition of bromodeoxyuridine triphosphates (Br-d. UTP) to the free 3’-hydroxyl ends of double or single stranded DNA fragments. This can be identified by FITC conjugated anti-Bromodeoxyuridine (Br. DU) antibodies Then tthese antibodies can be analyzed using a flow cytometer or a fluorescence microscope. 3/8/2021 Dr Atef Masad 19

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o TUNEL staining relies on the ability of the enzyme terminal deoxynucleotidyl transferase to

o TUNEL staining relies on the ability of the enzyme terminal deoxynucleotidyl transferase to incorporate labeled d. UTP into free 3'hydroxyl termini generated by the fragmentation of genomic DNA into low molecular weight double-stranded DNA and high molecular weight single stranded DNA 3/8/2021 Dr Atef Masad 22

o TUNEL staining may also be used to detect DNA damage associated with non-apoptotic

o TUNEL staining may also be used to detect DNA damage associated with non-apoptotic events such as necrotic cell death induced by exposure to toxic compounds and other insults , and TUNEL staining has also been reported to stain cells undergoing active DNA repair 3/8/2021 Dr Atef Masad 23

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