I am looking for a Bioengineering tutor who can teach me for my exam. You will need to answer many practice questions and explain me the answers accordingly. The sample questions are given below. If you are expert tutor in this field, you may apply-
Condition: Prakhar is a M.Sc. student who is working on the human gene, insulin, and wish to produce the protein for therapeutic purposes. Help him purify the protein where he has used Nterminal His-tagged-gene sequence to facilitate the protein purification process.
Guide Prakhar to choose the correct expression host. Which of the following features should be considered to choose the correct host?
Length of gene
Presence of introns
Post translational modifications
Toxicity to the host cells
Prakhar selected E. coli system for protein expression but when he grew the culture with pET28a expression vector, he could see low growth of the bacteria. He transformed the recombinant vector in the expression host with pLysS plasmid. The transformed plates are shown in the image below. Which of the following is FALSE for the observation shown below?
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A is E. coli strain with GOI and pLysS plasmid
B is E. coli strain with GOI and pLysS plasmid
pLysS helps in debilitating the leaky expression of GOI
Protein product of GOI is toxic to host cells
The opted chromatography was conducted and elute was collected. Refer to the image help Prakhar to understand the possible reasons why the eluent’s profile looks like this?
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Where, Lane 1 – Ladder, Lane 2 – Lysate, Lane 3 – FT, Lane 4 – Wash I_1, Lane 5 - Wash I_2, Lane 6 – Wash II_1, Lane 7 – Wash II_2, Lane 8 - Wash II_3 and Lane 9 – Elution1
N-terminal His-tag might lead to production of truncated protein
The elute can be a multimeric protein
Bacterial protein with high histidine content
a and c
Prakhar wish to confirm each band if it contains the desired protein of interest. Help him to select correct technique(s) to confirm the correct band.
Post conducting the 1st chromatography Prakhar observed that the purified elution contains four prominent bands at size difference of at least ~10 kDa. Which of the chromatography methods can he use to obtain pure protein?
Reverse phase chromatography
Ion exchange chromatography
Size exclusion chromatography
Prakhar needs to confirm the sequence of the recombinant plasmid he prepared. He used Sanger’s Sequencing of DNA molecules. Which of the following is correct for the sequencing method?
4’OH present, extends an already present DNA fragment, give radioactive signal
4’OH present, terminates DNA strand from extension, gives fluorescence
3’OH absent, terminates DNA strand from extension, gives fluorescence
3’OH absent, extends a new DNA fragment, gives chemical signaling
Prakhar isolated the recombinant plasmid for sequencing and diluted the sample with a dilution factor of 1:40. The UV-Vis Spectrophotometer Absorbance reading at 260 and 280 nm obtaining 0.42 and 0.21 readings respectively. So, calculate the concentration of plasmid in the dilute and concentrated plasmid samples.
DNAconc. in plasmid = 21 ng/ml; DNAconc. in plasmid diluent = 67.2 ng/ml
DNAconc. in plasmid = 21 μg/ml; DNAconc. in plasmid diluent = 67.2 μg/ml
DNAconc. in plasmid = 21 ng/ml; DNAconc. in plasmid diluent = 0.52 ng/ml
DNAconc. in plasmid = 21 μg/ml; DNAconc. in plasmid diluent = 0.52 ug/ml