A radioactively labeled probe is created by attaching a radioactive isotope, such as phosphorus-32 or carbon-14, to a nucleic acid molecule (DNA or RNA). This is typically achieved through chemical methods that incorporate the radioactive isotope during the synthesis of the nucleic acid or by enzymatic labeling, where enzymes incorporate labeled nucleotides into the growing nucleic acid strand. The resulting probe can then be used in various applications, such as hybridization assays, to detect specific sequences of nucleic acids. Proper safety protocols must be followed due to the radioactive materials involved.
A radioactively labeled probe is made by attaching a radioactive isotope to a nucleic acid molecule, such as DNA or RNA, which is complementary to the target sequence of interest. This is typically done by incorporating the radioactive nucleotide during the synthesis of the probe or by labeling the probe post-synthesis through various chemical methods. The choice of isotope, such as phosphorus-32 or sulfur-35, depends on the specific application and detection requirements. After labeling, the probe can be used in techniques like hybridization to detect specific nucleic acid sequences in various biological samples.
In the experiment, the scientist uses a radioactively labeled probe derived from yeast DNA to identify complementary sequences in a sample. The probe hybridizes to a small segment, indicating that this segment contains sequences complementary to the yeast DNA. This hybridization suggests a potential relationship or functional similarity between the yeast DNA and the target segment, which could lead to further investigations into gene function or evolutionary relationships. The results can provide insights into genetic expression or regulatory mechanisms in the organism being studied.
to complementary sequences in the target DNA, indicating successful binding between the probe and specific regions of the genome. This hybridization confirms the presence of the corresponding sequences in the sample being tested. The labeled probe can be used to visualize or quantify the target DNA, providing insights into gene expression, genetic variations, or the presence of specific mutations in the sample.
Radioactive nucleotide
DNA polymerase
To create radioactively labeled DNA, the molecule that must be labeled is a nucleotide. Specifically, one of the nucleotides (adenine, thymine, cytosine, or guanine) can be modified to include a radioactive isotope, such as phosphorus-32 or tritium. When these labeled nucleotides are incorporated into a DNA strand during replication or synthesis, the entire DNA molecule becomes radioactively labeled. This technique is often used in molecular biology for various applications, including tracking DNA synthesis and conducting hybridization experiments.
Scintillation counter
scintillation counter. APEX
Geiger Counter
The DNA separated into two classes: labeled DNA and unlabeled DNA. The labeled DNA contains the radioactively labeled nucleotides that were incorporated during DNA replication, while the unlabeled DNA represents the original, non-radioactively labeled DNA from the bacteria. The centrifugation process separated the DNA based on density, with the heavier labeled DNA migrating to a higher position in the centrifuge tube compared to the unlabeled DNA.
ER golgi vesicles that fuse with plasma membrane
Study the inheritance of traits that are not seen as a phenotype