Last updated: September 11, 2019
Topic: ScienceEngineering
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Sanger ‘s method or dideoxy sequencing or concatenation expiration all are same processs which are involved in usage of dideoxynucleotides ( ddNTP ‘s ) along with normal bases ( NTP ‘s ) nowadays in DNA. Dideoxynucleotides hold one excess H group at the 3 ‘ C as a replacement of hydroxyl group ( OH ) . Addition of ddNTPs Michigans entry of more base ( Speed, 1992 ) . Because it is non possible to organize phosphodiester bond among the dideoxynucleotide and following entrance nucleotide as a consequence of it DNA concatenation is stopped.

In first measure DNA is denatured by heat ensuing into individual DNA strand. Then tempering of specifically manufactured primer ( 3/ terminal is situated following to DNA sequence of involvement ) with one terminal of templet. This primer is wireless labeled for concluding sensing on gel. After fond regard of primer to DNA, whole solution is separated in four tubings labeled “ G ” , “ A ” , “ T ” and “ C ” . After that DNA polymerase is added along with dNTPs in each tubing. Add ddGTP, DDATP, ddTTP, and ddCTP in tubings severally in one centesimal concentration. Then synthesise DNA. ddNTPs will added in DNA templet alternatively of normal bases and halt concatenation growing. Run each tubing individually in different lane. Run the gel and expose it to UV and observe consequences ( Russell, 2002 ) .

Describe the Maxam-Gilbert sequencing method.

This procedure is besides called chemical sequencing. Allan Maxam and Walter Gilbert in 1976-1977 invent DNA sequencing process which stands on chemical alteration of DNA along with subsequent cleavage at peculiar bases ( Maxam and Gilbert. , 1977 ) . Method includes radioactive labeling on one terminal and refinement of the DNA fragment. As a consequence of chemical intervention splicing occurs at little part of one or two nucleotide out of four. This occurs in each of four reactions ( G, A+G, C, and C+T ) . It will ensue into series of wireless labeled fragments. Run gel after seting all four reactions in side by side lanes. Expose gel to X raies movie for consequences. It will demo series of sets in relation to radiolabel DNA.

Why is the Sanger method better?

Sanger method is simpler, efficient and in this process toxic chemicals used in less sums along with low degrees of radiation than the method of Maxam and Gilbert.

What are dideoxynucleotides triphosphates ( ddNTPs ) ?

One -OH is absent at place 3′-C and 2′-C of deoxyribose sugar in Dideoxy nucleoside triphosphates ( ddNTPs ) . One H is present alternatively of that OH. phosphodiester bond is formed at 5′-C to old base in concatenation, and at 3′-C place with following dNTP. So as a consequence of add-on of a ddNTP in DNA reproduction reaction will halt the growing of concatenation.

What is pyrosequencing?

This technique developed by Pal Nyren along with his pupil Mostafa Ronaghi at the Royal Institute of Technology in Stockholm in 1996. Pyrosequencing is procedure of DNA sequencing which is based on the sequencing by synthesis. In this process individual strand of DNA is sequenced via enzymatic readying of complementary strand. We detect activity of DNA polymerase by utilizing chemiluminescent enzyme. In this procedure one base brace is added and detected at a clip at each measure. Solutions of C, A, T, and G is added on stationary DNA templet and removed after reaction. As a consequence visible radiation is generated when specific base is attached with templet. This sequence of light and chemiluminescent signals enable us to find the sequence of the templet ( Ronaghi. , 1998 ) .

What do you sequence when you perform EST sequencing?

Transcribed complementary DNA sequence is determined by utilizing expressed sequence ticket or EST sequencing. It is used in finding of cistron sequencing ( Adams et al. , 1991 ) .

What does this image show ( to the left? , to the right? )

Picture shows sets of G, C, A, and T on gel. We can do sequence of DNA templet from this information by alining these sets harmonizing to sequence of sets observed on gel. Then image shows dyes that indicates different bases and concluding consequences in curve or pick signifier.

How can you acquire the images above? What I mean is which methods you use to visualise the sequences depicted.

This type of image is observed in Sanger methods or concatenation expiration method.

What is rhythm sequencing?

This sequencing procedure ab initio produced by Fred Sanger. It is now developed into rhythm sequencing reactions. In this technique, reaction has fluorescent dyes. An machine-controlled Deoxyribonucleic acid sequencing machine is used for analysis of Deoxyribonucleic acid fragments developed during the reaction. Finally we get order of nucleotide sequence. In this technique rhythms of DNA Denaturation, tempering and extension takes topographic point.

Is it possible to sequence RNA?

First convert RNA into complementary DNA via contrary written text is needed and so we sequence cDNA and sequencing information about RNA.

Describe sequencing by microarray hybridisation!

Deoxyribonucleic acid microarray engineering is used in DNA sequencing. It involves in 1000 of series of DNA microscopic musca volitanss oligonucleotides, known as characteristics. Each topographic point holding picomoles of peculiar DNA sequence called investigations or newsmans. These investigations are used for hybridisation of DNA or complementary DNA called mark. This is done in high tightness conditions. This investigation can so be quantified and observed by labeling mark with fluorophore Ag or chemiluminescence for finding of peculiar sequence in mark. In microarray 1000s of investigations are used so many testicles are used in analogue. This technique is used for analyzing difference in look degrees and individual base polymorphisms in mutant genome.

The basic rule of technique is between two complementary strands of DNA H bond is present. Bond strength is straight depends upon the base brace. Merely strong bonds remain integral and hybridized after rinsing. So coevals of signal from florescent label mark depends on strength of bonds and hybridisation. Final signal power depends on measure of adhering between mark and investigation nowadays in the topographic point. In this technique comparative quantification is measured and placing characteristics called as place ( Pollack. , et al 1999 ) .