Terminal Transferase
Terminal Transferase - Related Videos
05:32
Terminal Transferase-Mediated dUTP Nick End-Labeling—TUNEL Assay: An In Situ Method to Detect DNA Fragmentation in Apoptotic Cells
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2025
In this video, the TUNEL assay is performed to detect the presence of apoptotic cells in a sample. The study involves using a special DNA polymerase - terminal deoxynucleotidyl transferase - that catalyzes the addition of labeled dUTPs to the 3' terminus of fragmented DNA, which can be observed and identified under a fluorescence microscope.
01:44
Termination of Translation
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2020
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
07:37
Using Terminal Transferase-mediated dUTP Nick End-labelling (TUNEL) and Caspase 3/7 Assays to Measure Epidermal Cell Death in Frogs with Chytridiomycosis
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Cited by 3 •
2018
We quantify epidermal cell death in frogs with chytridiomycosis using two methods. First, we use terminal transferase-mediated dUTP nick end-labelling (TUNEL) in situ histology to determine differences between clinically infected and uninfected animals. Second, we conduct a time series analysis of apoptosis over infection using a caspase 3/7 protein analysis.
07:46
An In Vitro Assay to Detect tRNA-Isopentenyl Transferase Activity
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Cited by 3 •
2018
Here, we describe a protocol for the biochemical characterization of the yeast RNA-modifying enzyme, Mod5, and discuss how this protocol could be applied to other RNA-modifying enzymes.
15:16
Loading Drosophila Nerve Terminals with Calcium Indicators
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Cited by 17 •
2007
Calcium is a ubiquitous messenger in the nervous system, essential for triggering neurotransmitter release and changes in synaptic strength. Here we demonstrate a technique for loading Ca2+-indicators into Drosophila nerve terminals. We also demonstrate fabrication of the required apparatus and emphasize points critical for the technique's success.
FAQs
The free 3′ hydroxyl group provides the reactive DNA end required for nucleotide incorporation. Terminal transferase acts when this end is exposed, so the availability and position of the 3′ end determine whether DNA extension can occur. This end-directed activity explains why the enzyme is useful for modifying DNA termini and studying processes that generate or process DNA ends.
Unlike a template-dependent DNA polymerase, Terminal Transferase does not read a complementary DNA strand to determine the next nucleotide. It can therefore add deoxynucleotides in a way that produces variable sequences rather than copying preexisting sequence information. This distinction makes its activity especially relevant to DNA-end modification and the generation of sequence diversity.
During V(D)J recombination in developing lymphocytes, Terminal Transferase can add nucleotides at DNA junctions without relying on a template. These added bases change the sequence where gene segments join, creating additional variation among the resulting DNA arrangements. That junctional diversity expands the range of genetic information available during immune system development.
In laboratory methods, terminal transferase activity can be used to label DNA ends or extend them with added nucleotides. These applications take advantage of the enzyme’s ability to act directly at a free 3′ end without requiring a template. Consequently, researchers can investigate DNA termini or create modified DNA ends for experimental analysis.
Measuring terminal transferase activity can help identify immature lymphoid cells because the enzyme is associated with developmental stages in which immune-cell DNA rearrangement occurs. Activity measurements therefore provide a biological marker that complements cellular investigation. This use connects an enzymatic property with the development of lymphocytes and the formation of diverse immune-system components.
Studies of terminal transferase activity link local changes at DNA ends with broader questions about genome organization and immune development. Its ability to create variable sequences at recombination junctions offers a way to examine how DNA rearrangement contributes to lymphocyte maturation. Laboratory analysis can therefore address both the molecular behavior of DNA ends and its biological consequences.