Various Phases that Make Up the Cell Cycle

The two main stages that occur in the cell cycle are interphase and mitosis. In the majority of the cell cycle, the cells spend most of their time during interphase of the cell cycle. In synchrony, the cells undergo three stages, two growth stages and DNA replication. During interphase, the cells undergo their initial stroma (G1). During G1, protein and RNA synthesis occurs, allowing cells to grow and mature. (Cooper, Geoffrey M) G1 is very important as it controls the rate of cell growth and development.

When replicating chromosomally packaged DNA, S phase or synthesis is the phase of the cell cycle. This phenomenon is an important aspect of the cell cycle, since replication allows each cell produced by cell division to have the same genetic makeup. (The details of how this replication is done is contained in the DNA replication SparkNote of the SparkNotes series specialized in molecular biology.) Many events other than chromosomal replication occurred during the S phase It was. Cell proliferation continues throughout the S phase at the same rate as the synthesis of many proteins and enzymes involved in DNA synthesis. After DNA replication is complete, the cells contain twice as many normal chromosomes and are ready to enter the stage called G2.

Cell cycle analysis is a method in cell biology that uses flow cytometry to distinguish cells at different stages of the cell cycle. Prior to analysis, cells were permeabilized, treated with fluorescent dye and the fluorescent dye quantitatively stained DNA, typically propidium iodide (PI). Therefore, the fluorescence intensity of cells stained at a particular wavelength is related to the amount of DNA they contain. Since the cellular DNA content is replicated in the S phase of the cell cycle, G 0 phase and G 1 phase (before S phase), S phase, G 2 phase and M phase (S The relative number of cells can be determined. Fluorescence is twice that of G0 / G1 phase cells. Abnormal cell cycle is a symptom of various cell injuries such as DNA damage, and cells may interrupt cell cycle at specific checkpoint to prevent conversion to cancer cells (carcinogenic).