Check the publication:
"A novel Assay to Measure Loss of Plasma Membrane Asymmetry During
Apoptosis of Adherent Cells in Culture"
Manon van Engeland et al., Cytometry 24:131-139(1996)
Good luck.
Kjartan Egeberg
Inst. of Canser Research and Mol. Biol.
N-7005 Trondheim
Norway
E.mail: kjartan.egeberg@medisin.ntnu.no