North Dakota State University defines a DNA probe as a small piece of nucleic acid (typically single-stranded DNA) that is used to detect complementary stretches of DNA. DNA probes used in hybridization experiments are labeled so that they can be visualized.
As Wikipedia explains, DNA probes are typically labeled with either radioactive or fluorescent bases. It is more common to use fluorescent DNA probes because a variety of different fluorescent wavelengths can be chosen, which allows scientists to hybridize more than one probe to a given sample at a time.
According to "Human Molecular Genetics," DNA probes can be used for a variety of different molecular biology techniques. When used with a Southern or northern blot, DNA probes can be used to detect size fragments of a gene or other segment of DNA in question.
DNA probes can also be used for fluorescence in situ hybridization techniques, in which chromosomes are denatured on microscope slides. This method allows for the detection of larger chromosomal aberrations, including broken or fused chromosomes. Chromosome painting techniques utilize in situ hybridization to paint metaphase chromosomes different colors, which makes chromosome mapping easier. This technique can also be used to detect chromosome sequences that have been conserved between different species.Learn More
DNA methylation is a genetic signaling tool. This process locks genes into the "off" position. This process is crucial for cell differentiation, genomic imprinting, X-chromosome inactivation, chromosome stability and embryonic development.Full Answer >
According to HowStuffWorks, cytosine always pairs with guanine. The other two bases that pair together are thymine and adenine. These four bases make up nucleotides and are the building blocks of nucleic acids like DNA.Full Answer >
The DNA stored in each human cell has a total length of about 6 feet, according to the Theoretical and Computational Biophysics Group at the University of Illinois. The DNA is stored inside a cell's nucleus so tightly that it only occupies 10 percent of the total cellular volume.Full Answer >
DNA sequencing is a technique used to determine the exact sequence of nucleotides in a DNA sample. Electrophoresis, a method for separating DNA fragments, is used when the DNA differs in length by only one base. DNA samples are placed in a gel and exposed to an electric field.Full Answer >