How to Perform Rate Asymmetry in Genomes

A genome contains all the biological information required to build and maintain a living organism. It is usually present in the form of deoxyribonucleic acid or DNA, which is further divided into discrete units called genes. The DNA replicates and makes an exact copy during the process of cell division. Gene duplication helps transfer functions and characteristics to new generation. However, the rate of duplication may also be asymmetric. This leads to development of new functions and evolution. Rate asymmetry often occurs freely in nature, but you can also demonstrate the procedure in a laboratory using cell lines.

Things You'll Need

• Human fibroblast cell lines
• Maintenance medium
• Gamma and UV radiation source
• Centrifuge
• Incubator
• Phosphate-buffered saline

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Instructions

• 1

  Incubate the human fibroblast cell lines in a medium containing chemicals such as thymidine, penicillin, glutamine and fetal bovine serum at 37 degrees Fahrenheit in an incubator chamber with 5 percent carbon dioxide.

• 2

  Expose the cell lines to light sources with gamma and ultraviolet radiation for 30 minutes. Place the cell lines back in the incubator for 18 to 24 hours.

• 3

  Make suspensions of the cell cultures in fresh growth medium and incubate again for one or two hours in the incubator.

• 4

  Use the alkaline sucrose sedimentation method to study the stability and structure of the DNA. Dilute the cells in 20 volumes of phosphate-buffered saline and centrifuge at 1,000 revolutions per minute for four minutes at an angle of 4 degrees. Mix the solution with sodium hydroxide and sodium chloride, then identify the DNA growth phase and structure for any changes.