Question

QUESTION 4 का 0.2 points Save A How does the DNA sequence work? Chain termination method with fluorescent labeled dideoxynucleotides Chain termination method with radioactive labeled dideoxynucleotides ODNA polymerase he ол All of these

Answer 1

Ans.

The answer is 'All of these'.

Explanation:

Sanger Sequencing,also called as the 'Chain termination sequencing' is sequencing method used to determine the nucleotide sequence of DNA,developed by Frederick Sanger in 1977.This method of DNA sequence is based on the amplification of DNA fragment that is to be sequenced,by DNA polymerase with the addition of modified nucleotides,dideoxynucleotides (ddNTPs).The classical version of chain-termination method require a DNA template which is single stranded,DNA primer,DNA polymerase,deoxynucleotidetriphosphates(dNTPs) and modified nucleotides,that is ddNTPs,which terminates the DNA strand elongation.Since these chain-terminating nucleotides lack 3'-OH group which is required for the formatio of phosphodiester bond between the two nucleotides,the DNA polymerase will cease extension of DNA when a ddNTP is added.These ddNTPs when radioactively or fluorescently labeled,can be detected in an automated sequencing machine.The sequencing method includes tagging with either radioactive labeled dideoxynucleotide or flouorescently labeled ddNTPs and primers.For radioactive labeling radioactive phosphorus is used and while for fluorescent labeling a fluorescent dye is used.

Thus,all the three are the part of a DNA sequence and hence the answer should be ' All of these'.