DNA and RNA Analysis

DNA Facts

• DNA (Deoxyribonucleic Acid) is a molecule that stores genetic information in cells.
• DNA copies itself exactly for new cells.
• Chromosomes are made of DNA.
• DNA contains the instructions for making proteins within the cell.

Importance of DNA Study

• The study of DNA is essential to all life on earth.
• Medical benefits of DNA study include disease detection, treatment, and prevention.
• DNA study is important for the development of crops.
• DNA study is used in forensics.

DNA Structure

• DNA is a polymer composed of repeating subunits called nucleotides.
• DNA consists of two long strands, each a chain of nucleotides.
• Nucleotides consist of phosphate, carbon sugar (deoxyribose), and nitrogen base.
• The two strands twist around a central axis to form a double helix.

Nitrogenous Bases

• There are four types of nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
• Adenine can bond only with thymine (A-T or T-A).
• Cytosine can bond only with guanine (C-G or G-C).
• This is called the base pair rule.

DNA Translation

• DNA is in the nucleus.
• To make proteins, DNA must get its instructions to the ribosomes.
• DNA uses messenger RNA (mRNA) to transport its instructions.

RNA

• RNA (Ribonucleic Acid) consists of only one strand of nucleotides.
• RNA has ribose (a 5C sugar) NOT deoxyribose.
• RNA has uracil (U) as a nitrogenous base NOT thymine.

DNA by the Numbers

• Each cell has about 3 meters of DNA.
• The average human has 300 trillion cells.
• The average human has enough DNA to go from the earth to the sun more than 400 times.
• DNA has a diameter of only 0.000000002 meters (2 x10-9m).

DNA and RNA Extraction

• To study or manipulate nucleic acids, DNA or RNA must first be isolated or extracted from cells.
• DNA or RNA extraction involves breaking open cells, destroying unwanted macromolecules, and separating the desired molecules.
• Fluorometric DNA quantitation provides key advantages such as increased sensitivity, high selectivity for double-stranded DNA, and improved contaminant tolerance.

DNA Analysis

• Single nucleotide polymorphisms (SNP) genotyping is a process for analyzing genetic differences among individuals.
• SNP genotyping is used to identify disease-related mutations in various species.
• Electrophoresis is a method for separating and analyzing large molecules, such as proteins or nucleic acids, by migrating a colloidal solution through a gel under the influence of an electric field.
• Polymerase chain reaction (PCR) is a technique for creating multiple copies of DNA from a sample.

Gel Electrophoresis

• Gel electrophoresis is a technique used to separate molecules on the basis of size.
• Gel electrophoresis depends on the negatively-charged ions present on nucleic acids at neutral or basic pH.
• Nucleic acids are loaded into a slot near the negative electrode of a porous gel matrix and pulled toward the positive electrode at the opposite end of the gel.
• Smaller molecules move through the pores in the gel faster than larger molecules, separating them on the basis of size.

Polymerase Chain Reaction (PCR)

• PCR is a technique used to amplify specific regions of DNA for further analysis.
• PCR is used for cloning gene fragments, identifying contaminant foreign DNA, and amplifying DNA for sequencing.
• Primers—short pieces of DNA complementary to each end of the target sequence—are combined with genomic DNA, Taq polymerase, and deoxynucleotides.
• Reverse transcriptase PCR (RT-PCR) is similar to PCR, but cDNA is made from an RNA template before PCR begins.