# Cell cycle analysis

### From OpenWetWare

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C period = the time for a round of chromosome replication | C period = the time for a round of chromosome replication | ||

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D period = the time between the end of a round of chromosome replication and cell division | D period = the time between the end of a round of chromosome replication and cell division | ||

- | #Determination of initiation age (a<sub>i</sub>) and C+D: | + | #Determination of initiation age (a<sub>i</sub>) and C+D:[[Image:Theoretical_age_distr.jpg|left|200px]] |

- | [[Image:Theoretical_age_distr.jpg|left| | + | From flow cytometry analysis of cells treated with rifampicin and cephalexin (run-out histogram) the proportions of cells that had not initiated replication at the time of drug action (4-origin-cells, streaked) and cells that had initiated (8-origin-cells) can be estimated.The initiation age (a<sub>i</sub>) can be found from the theoretical age distribution described by this formula, |

- | From flow cytometry analysis of cells treated with rifampicin and cephalexin (run-out histogram) the proportions of cells that had | + | |

- | '''F = 2 - 2<sup>((τ- | + | '''F = 2 - 2<sup>((τ-a<sub>i</sub>)/τ)</sup>''' |

- | where F is the fraction of cells that had not initiated and | + | where F is the fraction of cells that had not initiated and τ is the generation time, or from the estimated graph of the theoretical age distribution (streaked portion). |

- | The C+D period is estimated from the initiation age ( | + | |

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+ | The C+D period is estimated from the initiation age (a<sub>i</sub>), the generation time (τ) and the number of generations spanned per cell cycle. | ||

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+ | Example: |

## Revision as of 08:59, 15 August 2008

**Cell cycle analysis of Escherichia coli cells**

C period = the time for a round of chromosome replication

D period = the time between the end of a round of chromosome replication and cell division

- Determination of initiation age (a
_{i}) and C+D:

From flow cytometry analysis of cells treated with rifampicin and cephalexin (run-out histogram) the proportions of cells that had not initiated replication at the time of drug action (4-origin-cells, streaked) and cells that had initiated (8-origin-cells) can be estimated.The initiation age (a_{i}) can be found from the theoretical age distribution described by this formula,

**F = 2 - 2 ^{((τ-ai)/τ)}**

where F is the fraction of cells that had not initiated and τ is the generation time, or from the estimated graph of the theoretical age distribution (streaked portion).

The C+D period is estimated from the initiation age (a_{i}), the generation time (τ) and the number of generations spanned per cell cycle.

Example: