Ni-NTA chromatography + 2 sequencing methods

During the washing step of His-tagged protein purification, why is a high concentration of imidazole included in the elution buffer?

• To enhance the binding of the His-tagged protein to the Ni-NTA resin

• To compete with the His-tag and wash away weakly bound contaminants

• To remove the His-tag from the protein before elution

• To increase the affinity of the His-tagged protein for the resin

What is the role of dideoxynucleotides (ddNTPs) in chain termination DNA sequencing?

• To act as primers for DNA synthesis

• To extend the DNA strand with additional nucleotides

• To increase the speed of DNA polymerase

• To terminate DNA strand synthesis at specific nucleotides

In the chain termination method of DNA sequencing, why are four different fluorescent markers used?

• To differentiate between the four types of ddNTPs (ddATP, ddCTP, ddGTP, ddTTP)

• To identify the length of each DNA fragment

• To ensure efficient primer annealing

• To increase the overall fluorescence signal during detection

What is the consequence of incorporating a dideoxynucleotide (ddNTP) during DNA synthesis in the chain termination sequencing method?

• It allows for continuous DNA synthesis without interruption.

• It speeds up the synthesis of the DNA strand.

• It terminates the DNA strand elongation at that point.

• It initiates a new round of DNA synthesis.

In Maxam-Gilbert sequencing, which chemical reagent is specifically used to modify and cleave cytosine residues?

• Dimethyl sulfate (DMS)

• Hydrazine

• Formic acid

• Piperidine

During the Maxam-Gilbert sequencing process, what is the role of piperidine?

• To label the DNA fragment with a radioactive isotope

• To separate the DNA fragments by size in gel electrophoresis

• To cleave the sugar-phosphate backbone at chemically modified sites

• To selectively methylate cytosine residues

In Maxam-Gilbert sequencing, which chemical reagent is specifically used to modify guanine residues?

• Dimethyl sulfate (DMS

• Formic acid

• Hydrazine

• Piperidine

Which chemical reaction in Maxam-Gilbert sequencing leads to the cleavage of both cytosine and thymine residues?

• Formic acid treatment

• Dimethyl sulfate (DMS) reaction

• Piperidine cleavage

• Hydrazine with high salt concentration

Which chemical reagent in Maxam-Gilbert sequencing is used to modify both adenine and guanine residues?

• Dimethyl sulfate (DMS)

• Formic acid

• Hydrazine

• Piperidine

Which step in Maxam-Gilbert sequencing involves separating DNA fragments by size?

• Chemical treatment

• Cleavage

• Gel electrophoresis

• Autoradiography