DNA fragmentation kit

Hi, I am now planning to buy kits for quantitating DNA fragmentation. I quoted the price of TUNEL kit, but it is very expensive. Do anyone have any recommendation?

If you can get your cells into suspension, do not need to look at death in "colonies" of cells, and have access to any kind of flow cytometer/FACS machine, the easiest (and cheapest) way to go is a direct propidium iodide staining for DNA fragmentation. Tis method can be further refined for apoptosis using dual staining with Annexin V conjugates and propidium iodide or related rgt.
I can give you more specific/protocol details if you state what kind of cells you are studying.

Hi Samm,

Thanks for your advice first.
My lab also used this method to see apoptosis, but it is a rather qualitative method than a quantitative one. We use PI to see cell cycle and annexin-V-FITC to show early and late apoptosis.
I see paper that some people use 7AAD to quantify apoptosis, and TUNEL or Roche Cell Death Detection Kit. But the later two are very expansive.
Do you try other methods?

7-AAD gives essentially similar results to PI - you do have to change your Annexin -conjugate when you use that (can't use FITC). I've used ApoTag, but don't think its worth wrt the cost -to-benefit ratio. You can use TUNEL or these assays as a comparision standard though. I've found that if you carefully set your G0/G1 peak of your control cells (representing the population with 2n amount of DNA) at a fixed channel value each time, and gate out debris with a PI (FL-2) area v/s width plot, the PI-Annexin method is both qualitative AND quantitative.
You can also observe the nuclear blebbing and DNA frag with the Hoechst family dyes (3xxxx), but that is very qualitative (pretty pictures though!).

You might consider using TUNEL without buying the kit. Just purchase TdT enzyme (Fermentas offers good and cheap one) and labeled dUTP (also Fermentas). The composition of solutions and the protocol are described in TUNEL kit manual from Roche.