title: Estimating cell death in G(2)M using bivariate BrdUrd/DNA flow cytometry.
abstract: BACKGROUND
  In an accompanying paper (Asmuth et al.) it was found necessary to include cell death explicitly to estimate parameters of cell proliferation. The use of bivariate flow cytometry to estimate the phase durations and the doubling times of cells labeled with thymidine analogues is well established. However, these methods of analysis do not consider the possibility of cell death. This report demonstrates that estimating cell death in G(2)/M is possible.
  
  
  METHODS
  Mathematical models for the experimental quantities, the fraction of labeled undivided cells, the fraction of labeled divided cells, and the relative movement were developed. These models include the possibility that, of the cells with G(2)/M DNA content, only a certain fraction will divide, with the remainder dying after some time T(R). Simulation studies were conducted to test the possibility of using simple methods to estimate phase durations and cell death rates.
  
  
  RESULTS
  Cell death alters the estimates of phase transit times in a rather complex manner that depends on the lifetime of the doomed cells. However, it is still possible to obtain estimates of the phase durations of cells in S and G(2)/M and the death rates of cells in G(2)/M.
  
  
  CONCLUSIONS
  The methods presented herein provide a new way to characterize cell populations that includes cell death rates and common measurements of cell proliferation.
authors.affiliation: Department of Biostatistics and Applied Mathematics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009, USA. rawhite@mdanderson.org
authors.forename: R Allen
authors.initials: RA
authors.lastname: White
authors.forename: David M
authors.initials: DM
authors.lastname: Asmuth
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Li
authors.forename: Lisa
authors.initials: L
authors.lastname: Reece
authors.forename: Richard B
authors.initials: RB
authors.lastname: Pollard
authors.forename: Mostafa
authors.initials: M
authors.lastname: Nokta
authors.forename: James F
authors.initials: JF
authors.lastname: Leary
authors.forename: Nicholas H A
authors.initials: NH
authors.lastname: Terry
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000737:chemistry*; D016923:Cell Death; D049109:Cell Proliferation; D002469:Cell Separation; D004247:DNA / Q000032:analysis*; D005434:Flow Cytometry; D016195:G2 Phase; D006801:Humans; D008938:Mitosis; D008954:Models, Biological; D011336:Probability
chemical_list: D004247:DNA; D001973:Bromodeoxyuridine