# Cell cycle analysis

(Difference between revisions)
 Revision as of 10:21, 15 August 2008 (view source)← Previous diff Revision as of 10:24, 15 August 2008 (view source)Next diff → Line 22: Line 22: Example: Example: - [[Image:DNAHistogram.jpg|left|200px]] + [[Image:DNAHistogram.jpg|left|100px]] 4-origin-cells: 23 % 4-origin-cells: 23 % Line 29: Line 29: Initiation age (ai): 5 min Initiation age (ai): 5 min + + + + [[Image:C+D_1.jpg|left|250px]]

## Revision as of 10:24, 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

1. Determination of initiation age (ai) 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 (ai) 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 (ai), the generation time (τ) and the number of generations spanned per cell cycle.

Example:

4-origin-cells: 23 %

Generation time (τ): 27 min

Initiation age (ai): 5 min