Transcript: Assay Show 4: Kinetic Apoptosis Assay using Caspase 3/7 Detection Reagent and Suspension Jurkat Cells

Welcome to the assay show. This video will show you how to perform a kinetic apoptosis assay on the Celigo image cytometer using caspase 3/7 detection reagent and suspension Jurkat cells.

Let me first take a moment and describe the assay principle.

  • DEVD is a caspase 3/7-specific sequence that is coupled with a DNA dye molecule.
  • This substrate can freely diffuse across the cell membrane in live cells.
  • Once inside apoptotic cells, the caspase 3/7 protein recognizes and cleaves the DEVD sequence and releases the DNA probe.
  • Once the probe enters the nucleus it binds to the DNA producing a bright green fluorescent signal.

After staining, the Celigo was used to acquire whole well bright field and Caspase 3/7-Green images

The Celigo software automatically analyzes the captured images and reports the total number of green, caspase positive cells in the entire well

The captured bright field images were not analyzed and were used to monitor cell morphology

Today I will show you a kinetic apoptosis assay that was performed using suspension Jurkat cells that were treated with 3 micromolar staurosporine.

To achieve the best accuracy of your cell plating, first, measure the cell concentration by using a Cellometer automated cell counter.

Mix 20 microliters of the cell sample and 20 microliters of trypan blue

Load 20 microliters of stained sample into the Cellometer chamber slide and perform a cell count to acquire cell number, concentration and viability of your sample.

Based on the measured concentration of your cells, adjust the volume and per well, plate 20,000 cells with caspase 3/7 along with either 3 micromolar staurosporine or vehicle control in a volume of 200 microliters.

Centrifuge the plate to settle the cells to the bottom of the well.

Allow the plate to incubate at 37 degrees Celsius for 30 minutes and image the plate to acquire, time point zero.

Subsequently image the plate at 2 hr, 6 hr and 8 hr after drug treatment.
The entire plate with whole-well imaging is captured in 15 minutes
The analyzed results are displayed in a plate-based format showing a thumbnail picture and the number of apoptotic cells for each analyzed well.

Let’s take a closer look at a treated sample in well D9.

By double clicking on a well, the whole well image appears for review.
We can zoom in to look at the cell morphology in the bright field image and examine the staining of caspase-positive cells.

By using the drop-down menu, we can quickly look at and compare samples captured at different time points

Direct cell counting of Caspase positive cells allows for the real-time monitoring of apoptotic events on a per-well basis

All the data can be exported to Excel as a .CSV file in a plate-based layout.

Each file that is exported to Excel contains the number of caspase 3/7 positive cells

Generated bar graphs show a time-dependent increase in the number of caspase 3/7 positive cells in the staurosporine-treated samples.

These and other assays are routinely performed on the Celigo

To learn more or schedule a free in-lab demonstration call us or visit nexcelom.com