This website uses cookies to ensure you have the best experience. Learn more

Ligase Chain Reaction Essay

1506 words - 7 pages

Ligase Chain Reaction (LCR)

Summary

Ligase chain reaction (LCR) is the method which detects a specific nucleotide sequence with some similarities to polymerase chain reaction. It is similar to polymerase chain reaction (PCR) as it uses DNA polymerase and specific primers designed to bind to the target. However, it is unlike to PCR as the primers are not used to amplify the DNA sequence between the primers. In the presence of target sequences, both primers will hybridize in such a way that one primer will lie directly to the second primer of the pair. In the presence of DNA ligase, these two primers are joined to form a single strand and the target sequence will have been effectively ...view middle of the document...

However, unlike PCR, the primers are not used to amplify the DNA sequence between the primers. Instead, if the target sequence is present, both primers will hybridize so that one primer will lie directly adjacent to the second primer of the pair. In the presence of DNA ligase, these two primers are joined to form a single strand and the target sequence will have been effectively duplicated. In the presence of a mutation or if the target sequence is not present, the primers will not bind and ligation will not occur. As the cycle is repeated, only the target sequence (if it is present) is amplified.

Allele-specific LCR employs four oligonucleotides, two adjacent oligonucleotides which uniquely hybridize to one strand of target DNA and a complementary set of adjacent oligonucleotides, which hybridize to the opposite strand. Thermostable DNA ligase will covalently link each set, provided that there is complete complementarity at the junction. Because the oligonucleotide products from one round may serve as substrates during the next round, the signal is amplified exponentially, analogous to PCR amplification. A single-base mismatch at the oligonucleotide junction will not be amplified and is therefore distinguished. A second set of mutant specific oligonucleotides is used in a separate reaction to detect the mutant allele.

History

Since its discovery in 1985, the polymerase chain reaction (PCR) has had a profound impact on detecting genetic and infectious diseases, identifying new genes, and unraveling the mysteries of protein-ligand recognition. Its universal utility is due to the specificity of amplification and ease of cycling made possible by the cloning and careful characterization of a thermostable polymerase from Thermus aquaticus. Likewise, cloning of a thermostable ligase enabled a new amplification method, termed ligase chain reaction (LCR), to both amplify DNA and discriminate a single base mutation. Although these DNA amplification techniques are new, they bring to fruition the "enzymes as reagents" philosophy expounded by A. Kornberg and I.R. Lehman a quarter of a century ago.

Principle of Ligase Chain Reaction

The principle of LCR is based in part on the ligation of two adjacent synthetic oligonucleotide primers, which uniquely hybridize to one strand of the target DNA. The junction of the two primers is usually positioned so that the nucleotide at the 3' end of the upstream primer coincides with a potential single base-pair difference in the targeted sequence. This single base-pair difference may define two different alleles, species, or other polymorphisms correlated to a given phenotype. If the target nucleotide at that site complements the nucleotide at the 3' end of the upstream primer, the two adjoining primers can be covalently joined by the ligase. The unique feature of LCR is a second pair of primers, almost entirely complementary to the first pair, that are designed with the nucleotide at the 3' end of the...

Other Essays Like Ligase Chain Reaction

Living In A Cashless Society Essay

1637 words - 7 pages Money in a traditional sense no longer exists. Money is becoming much of a concept than a physical material, and most ordinary bitter have not see the reality of the switch. People today are using credit and debit cards on a regular basis and in everyday situations such as meal purchased at fast food, highway tolls, clothing, groceries, gas stations, etc. all of these means of systems could be regarded as a cashless society or world. The question

The French And Indian War: The "Real" First World War

1955 words - 8 pages The Seven Years War, or more commonly referred to as “The French and Indian War”, has been called the true First World War. In this book The French and Indian War: Deciding the Fate of North America, the author and historian Walter R. Borneman paints a detailed and elaborate picture that justifies the claim of it being the first true war of global proportions. If ever there truly was a climax to the never ending feud of the European powers

Is The Use Of Animals In Medical Research A Necessary Measure?

1513 words - 7 pages experiment cannot be accurately extrapolated to humans. The skin irritant test involves placing a chemical on a shaved patch of skin and using another shaved patch as the control. It is used to evaluate the potential of a substance to cause irreversible damage to the skin (“Types of”). Due to the variety of responses to the chemicals among different species of animals, it is extremely difficult to conclude that the same reaction will occur on

Education And The Evolving Job Market

2363 words - 10 pages The lives of students today are changing. They are preparing for lives and jobs that have never before existed. If teachers hope to have a significant and worthwhile impact on these quickly changing lives, they must change the way they think, prepare, and instruct our future generations. Children cannot afford to have teachers who remain stagnant in their methods and ideals. Students crave instructors that are willing to allow them to tap

Young And Relentless

1737 words - 7 pages There are numerous influences that can be responsible of teenager’s behaviors and attitude as they develop. One factor that is important to these behaviors is parental figures being over involved or uninvolved in their children’s lives. Many of these effects include illegal substance abuse, rising sexual activity, underage alcohol consumption, and tobacco use. Studies show parental participation plays a key role in the characteristics developed

The Natural Law Theory

1231 words - 5 pages Obeying by the natural law theory is the only true and moral way to live life; especially a life lived in God’s image. God’s presence is a guiding factor to obtaining a moral and virtuous life, which can only be obtained by following the natural law theory. God created a set of laws as a supreme guide for humans to live life, like any law these laws were created to ensure wellbeing for everyone. The laws he created are the civil law, the natural

Resolved: Presidential Signing Statements Threaten To Undermine The Rule Of Law And The Separation Of Powers

1811 words - 8 pages The subject of signing statements has created much debate among the houses of Congress, government officials, and the public alike. These signing statements fall under the categories of constitutional and legislative history signing statements. Constitutional signing statements are those in which the president deems certain provisions of the legislation as unconstitutional, therefore they should not be enforced (Bradley & Posner, 2006

Oppressive Systems Of Government In Egypt And Animal Farm

1529 words - 7 pages As in Egypt, Orwell demonstrates through his allegorical novel “Animal Farm” that leaders are able to establish and maintain power over a people, and in turn create an oppressive and corrupt government system. Orwell shows the significant difference in the education and levels of knowledge in the animals, and how the government takes advantage of this difference. The split between the levels of intelligence is portrayed in the first chapter when

The Pathway To Psychosis

1415 words - 6 pages “How all occasions do inform against me” is a line from act IIII, scene IIII of William Shakespeare’s Hamlet. This line, spoken by Hamlet, expresses his emotional state as he is currently overwhelmed by the death of his father, the king of Denmark, and the situation surrounding it. After Hamlet learns of his father’s death he finds out that his mother has married Claudius, Hamlet’s uncle. On top of all of that, Hamlet soon after

Rated “M” For “More Censorship Not Needed”

1241 words - 5 pages Since the moment video games became a commercial success there have been people who have pushed for unfair amounts of censorship to be placed upon the content of the games and its availability to children. These groups push for increased regulations on content but there is already an appointed group to handle this issue, the ESRB. Even though there has been an increase in mature content in the video game industry, increased censorship is not

Four Components Of A Legally Astute Social Media Marketing Manager

1914 words - 8 pages With the advances in technology constantly changing companies have to find better ways to market their products to consumers. The explosion of Facebook has given companies a way to market products to consumers. Examine how a legally astute manager can use social media to his advantage. Review different forms of dispute resolution and determine which one works the best. What is the best course of action, the government can use to

Related Papers

Biology Key Skills Essay

2176 words - 9 pages polymerase catalyzes the formation of the hydrogen bonds between each arriving nucleotide and the nucleotides on the template strand. In addition to catalyzing the formation of Hydrogen bonds between complementary bases on the template and newly synthesized strands, DNA polymerase also catalyzes the reaction between the 5' phosphate on an incoming nucleotide and the free 3' OH on the growing polynucleotide. As a result

The Separation Of Capital Ownership And Control

1577 words - 7 pages The argument of whether the separation of capital ownership and control is an efficient form of organization has constantly been a controversial issue. The criticism whether the controllers’ act is in the best interest of the owners’ wills never end as long as hired managers operate management. As the number of public companies has been increasing over the course of this century, meanwhile the American style of contact based corporation has

The Versatility And Flexibility Of Oled's

1014 words - 5 pages In April 1, 2002, organic light emitting diodes gain rise in the scientific community with their published, more practical form at Ames Laboratory. “Scientists at the U.S. Department of Energy's Ames Laboratory, in collaboration with scientists at the University of Michigan, Ann Arbor, have developed and demonstrated a novel, fluorescence-based chemical sensor that is more compact, versatile and less expensive than existing technology of its

Comparing The Moral Virtues Of Antony And Julian The Apostate

1103 words - 5 pages Roman emperor Julian the Apostate and Christian leader Antony both exhibited many qualities of character during their existence. Both of them led very distinctive lives although shared several ethical values. Book 25 of “The Later Roman Empire” and the book “Early Christian Lives” show concrete evidence of this. In the following essay, I will argue how both leaders’ lives were devoted to their religious beliefs and their mutual cardinal virtues