07.01.2014 Views

LIFE09200604007 Tabish - Homi Bhabha National Institute

LIFE09200604007 Tabish - Homi Bhabha National Institute

LIFE09200604007 Tabish - Homi Bhabha National Institute

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Materials and Methods<br />

Immunophenotyping: 1x10 6 cells from LCLs were incubated separately with PE<br />

labeled primary mouse anti-CD3 (T cell marker), anti-CD19 (pan-B cell marker) and<br />

anti-CD56 (NK cell marker) antibodies for 1 h on ice (antibodies used in this<br />

experiment were kind gift from Dr. Shubhada Chiplunkar, Immunology department,<br />

ACTREC). The cells were washed and suspended in 500 µl FACS buffer. Further cells<br />

were passed through BD TM 1 ml 26G ½ syringe to break any cell aggregates or clumps<br />

and analyzed on Flow Cytometer (FACS Calibur, BD Biosciences, USA) at 488 nm<br />

excitation. A minimum of 10,000 events were analyzed for each sample. Cellular debris<br />

was removed by gating on Forward vs. Side Scatter. Data analysis was done using<br />

CellQuest Pro software (BD Biosciences, USA).<br />

3.4.2 Ploidy analysis of LCLs:<br />

DNA ploidy is defined as diploid DNA represented as single G0/G1 peak on a<br />

histogram of test sample corresponding to the same DNA content represented as single<br />

G0/G1 at the same position in the histogram of control sample. DNA ploidy was<br />

measured by calculating DNA index (DI) which is the ratio between the channel<br />

number of G0/G1 peak on histogram of the cell line to the channel number of G0/G1<br />

peak of control PBLs. DNA content of the cell is measured by labeling the cells with<br />

Propidium Iodide (PI). PI is a fluorescent intercalating agent which is when excited at<br />

488 nm fluoresces red. It is routinely used to stain DNA to evaluate cell cycle analysis<br />

and cell viability.<br />

Materials:<br />

1. 70% ethanol<br />

2. Propidium Iodide (0.4 mg/ml)<br />

3. RNase A (1 mg/ml)<br />

4. 1ml 26G ½ syringe<br />

5. FACS tubes<br />

Method:<br />

1x10 6 cells from LCLs and control PBLs were washed and suspended in 500<br />

µl PBS. Equal amount of 70% alcohol was added to the cells very slowly and drop<br />

wise. The cells were then mixed gently and were incubated for 10 min/ RT. Further<br />

Cells were centrifuged at 1500 rpm/ 10 min/ RT and were fixed in 500 µl 70% ethanol<br />

at 4 °C for 1 h. These fixed cells can be stored in 70% alcohol for a long time at 4 °C<br />

till further use. At the time of ploidy analyses cells were centrifuged at 1500 rpm/ 10<br />

56

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!