We amplify a piece of DNA that is 400bp long. The Alu transposon is 300bp long.

Question

We amplify a piece of DNA that is 400bp long. The Alu transposon is 300bp long. Explain how we can determine the presence of the Alu transposon with gel electrophoresis. What would the band pattern be if an individual has the Alu transposon on both homologous chromosomes (i.e., homozygous)? What would the band pattern be if an individual is heterozygous? What would the band pattern be if an individual does not have the Alu transposon? What is a primer dimer? What would you see if PCR amplification was unsuccessful?

Explanation / Answer

Alu transposons are found as inserts in the DNA as jumping gene.

a. band pattern on gel electrophoresis if an individual has Alu transposon on both homologous chromosomes: Since the condition is homozygous, then the sizeof the Fragment will be definitely larger than the DNA and Transposon itself. therefore it will ruyn slowly and will be marked above in the gel electrophoresis. And the DNA fragment of DNA will appear down because it will run fast.

b. Evn if itis heterozygous, there will be positive insert and we will obtain two or three bands again of larger size than the DNA fragment alone.

therefore the Bands will be obtained above in the gel but below homozygous bands.

while the DNA fragment without Alu will be obtained very down in the gel.

c. Primer dimer are the fragments of oligonucleotides obtained due to amplification of primer oligonucleotiode with pimer and lead to the formation of small Double stranded DNA fragment and will be seen as a Band but of very small size so it will run very fast and appear lowest in the Gel during electrophoresis.

d. If PCR amplification is failed, then we will not get any of the bands on the gel electrophoresis.

But there could be presence of primer dimer only.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.