Amgen Biotech Experience (ABE) Lab Practice Test

These questions are part of the practice quiz. Start practicing

• What is 'star activity' in restriction enzymes, and how can it be minimized?
• Which statement describes plasmid DNA?
• In the R- lane, what would indicate multiple plasmid configurations?
• Why are incubation time and temperature important in a transformation protocol?
• Why is sterile technique essential when handling plasmids and bacterial cultures in ABE labs?
• Describe the basic principle of DNA gel electrophoresis.
• What is a positive control in a PCR experiment?
• What is the purpose of a plasmid miniprep kit in cloning workflows?
• What is the role of the pbad promoter on the pARA-R plasmid?
• Why can a human gene be expressed in bacteria?
• Why did bromophenol blue move farther than xylene cyanole despite weight differences?
• Unexpected bands in Lab 4a are most likely due to which origin?
• Why is DNA loaded into the negative end of the gel electrophoresis box?
• After purifying plasmid DNA, which downstream application is commonly performed?
• In the absence of arabinose, what happens to transcription from PBAD?
• In cloning, the insert DNA is best described as the DNA fragment that is intended to be replicated within the host.
• Blue-white screening is used in cloning. What does a white colony indicate?
• Why would bacteria retain a gene that gives them resistance to antibiotics?
• Which solution contained a single dye?
• What is the importance of micropipettes?
• How would you interpret a gel showing no visible DNA bands in a sample lane but a clear ladder in the marker lane?
• What is the function of the PBAD element on the plasmid?
• What is one consequence of recombinant plasmids replicating independently in a cell?
• What happens when bacteria with the pARA-R plasmid are not given arabinose?
• Which factor minimizes star activity and non-specific cleavage in restriction enzyme reactions?
• Why is it important to include replicates in transformation or PCR experiments?
• Why is mFP placed in binding buffer?
• Why are precautions to avoid cross-contamination important when handling plasmids and bacterial cells?
• What indicates a DNA ladder is functioning properly in a gel run?
• In cloning experiments, why is it important to identify cells that have taken up the plasmid?
• What is the purpose of heat shock in transformation?
• Why can a bacterial cell produce a human protein from a human gene?
• In the described purification, how do high-salt binding conditions affect hydrophobic proteins in column chromatography?
• Which gene fragments are present in the recombinant plasmid used in this experiment?
• Which waste streams are typically used for used pipette tips and microcentrifuge tubes in ABE labs?
• What does the ampr gene encode on the pARA-R plasmid?
• What was the purpose of adding lysis buffer to cell culture?
• Gel electrophoresis separates molecules based on two properties. Which two properties are involved?
• In a transformation protocol where two plasmids with different resistance genes were mixed, how should you split the cultures?
• What is the purpose of the DNA ladder in gel electrophoresis?
• How is the information encoded in the rfp gene expressed as a trait?
• Why is the tip box kept closed during experiments?
• What is the relationship among genes, proteins, and traits?
• After running a gel, how can you verify the presence of the fragment of the expected size?
• Which component is required to initiate DNA synthesis in PCR?
• Why is ampicillin added to the agar plate in plasmid experiments?
• If the A260/A280 ratio is lower than 1.8, what does this indicate?
• In column chromatography, what happens to hydrophilic proteins?
• What is a multiple cloning site (MCS) and why is it useful?
• Why did red colonies appear only on LB/amp/ara plates and not on LB/amp plates?
• What instrument and wavelength are commonly used to quantify DNA in the lab?
• Why must pH be controlled when preparing buffers for enzymatic reactions?
• The PBAD promoter drives expression of which gene on this plasmid?
• If the procedure was performed correctly, how should the observed number of bands compare to the predictions?
• What is the AraC protein?
• To express red fluorescent protein in bacteria, which plasmid components are needed?
• Hydrophobic interaction chromatography relies on which protein property?
• What activity occurred in the 37°C water bath during the digestion step?
• Which of the following is not listed as a cause of a smear on an agarose gel?
• What evidence suggests you have the correct recombinant plasmid in the gel image?
• What type of bonds hold DNA base pairs together?
• What does an A260/A280 ratio of approximately 1.8–2.0 indicate for DNA?
• Why is it important to identify and verify a recombinant plasmid?
• Why is it possible for bacteria to make a human protein, such as insulin?
• What does it mean that the E. coli bacteria are 'competent'?
• Why was ampicillin included in the overnight culture?
• How does antibiotic resistance affect medical treatment outcomes?
• Which items should be checked as part of reagent verification before running the experiment?
• During purification, what happens to hydrophobic proteins bound to a hydrophobic resin when eluted?
• Which statement describes the basis for separation of red fluorescent protein in column chromatography?
• In a restriction digest, the R- tube serves as which type of control?
• Why is it useful to run a DNA gel before performing ligation or transformation?
• Which plasmid feature enables selection of bacteria that have taken up the plasmid?
• What is the purpose of soaking the gel in Ethidium Bromide and rinsing it with distilled water?
• In eukaryotic cells, DNA is found in which locations?
• If a plasmid contains two restriction sites for a given enzyme and both are cut, what is the expected result on a circular plasmid?
• If transformation efficiency is calculated as CFU per μg of DNA, what is the unit?
• What would happen if a plasmid lacked an origin of replication?
• What type of resin was used in the chromatography column?
• In a transformation protocol, what is the purpose of allowing cells to recover after transformation?
• Which statement correctly describes the purpose of antibiotic resistance markers in plasmids?
• Which instrument is commonly used to separate DNA by size in gene engineering workflows?
• Which dye has the smallest molecular weight?
• When quantifying DNA, what does absorbance at 260 nm primarily reflect?
• What is the function of a neutralized lysis buffer in plasmid minipreps?
• Which statement best describes a selectable marker in plasmids?
• In this protocol, what is the primary purpose of using hydrophobic interaction chromatography?
• In the R+ lane, which fragments are expected?
• The 4,495 bp ampR fragment would appear between which ladder marks?
• What does the term 'clone' refer to in molecular cloning?
• In gel electrophoresis, which property primarily determines the separation of DNA fragments?
• How might the column chromatography procedure be adjusted or modified to increase the purity of the red fluorescent protein sample?
• Which statement best describes the purpose of the first stop on a micropipette in a transfer?
• What properties of the amino acids in a protein relate to protein folding?
• Which strategy helps improve the reliability of results across replicates?
• How can a human gene be expressed in bacteria?
• What factor most limits the number of transformed colonies in a transformation experiment?
• In a plasmid transformation, what is the role of an antibiotic resistance gene?
• What is genetic engineering?
• In cloning, what is the role of a restriction enzyme site?
• What was the purpose of the Wash Buffer?
• Where is DNA located in prokaryotic cells?
• Which step in the transformation protocol is responsible for DNA uptake (Transformation)?
• Which description best matches binary fission in bacteria?
• What is the function of a promoter in a plasmid?
• What is a plasmid?
• What observation indicates complete digestion in the R+ lane?
• How do the R+ and R- tubes differ in a restriction digest setup?
• How can the conformation of a protein influence its function?
• Which base pairs with cytosine in DNA?
• In the R+ lane, where is the 807 bp rfp fragment relative to ladder marks?
• Which scenario could explain no colonies after transformation on antibiotic-containing media?
• Why did E. coli only grow on the P+ side of the LB/amp plate?
• What factor primarily influences the resolution of DNA fragments on an agarose gel?
• What is the function of BamHI and HindIII when applied to a plasmid?
• Which plasmid form migrates fastest?
• What does CFU stand for?
• What is the difference between genomic DNA and plasmid DNA?
• Which plasmid feature enables replication in the bacterial host?
• Which statement best describes the role of arabinose in this system?
• Which factor would most directly cause no colonies on selective plates after transformation?
• Sickle cell anemia is described as a disease resulting from defective red blood cells. What is the main type of cell involved?
• Which statement correctly describes DNA structure and base pairing?
• The para-R plasmid replicated in a bacterial cell may exist before digestion in which configurations?
• Restriction sites are typically identified by palindromic sequences. Which description matches a restriction site?
• What is the role of proteins in cells?
• Which statement about DNA gel band intensity is true?
• How do bands from linear fragments differ in appearance from plasmid bands?
• Name two buffers commonly used in molecular biology workflows and their general purpose.
• What is the purpose of a selectable marker in bacterial cloning?
• CFU stands for and what does it measure in bacterial culture?
• What happens when arabinose is present in the system?
• Why should you check reagents before a cloning procedure?
• What is a negative control in a PCR experiment?
• Why are negative controls important in transformation or PCR experiments?
• Which statement best describes the role of hydrophobic amino acids in protein folding?
• How is antibiotic concentration chosen for selection plates in transformation experiments?
• Which promoter controls expression of the red fluorescent protein in the presence of arabinose?
• In strawberry DNA extraction, what is the role of a detergent in the protocol?
• What is the primary purpose of wearing gloves, lab coat, and eye protection during ABE experiments?
• Define a plasmid and name two features commonly found on cloning plasmids.
• For the pARA-R plasmid used in cloning experiments, how many restriction sites are present for the enzymes used?
• What is the purpose of the gel loading dye containing glycerol or sucrose?
• What does OD600 measure?
• What is the formula used to calculate transformation efficiency? (include units)
• What are the sticky ends generated by BamHI and HindIII?
• Why is pipetting accuracy important in preparing a dilution series?
• Why is it important to have multiple copies of a recombinant plasmid within a cell?
• Which statement best describes DNA conservation and variation among organisms?
• Why are proteins sometimes called workhouse molecules?
• In a cloning workflow, digestion with BamHI and HindIII is used to do what?
• Gel electrophoresis is used to separate and identify plasmids and short DNA fragments by size. Which statement best describes its purpose?
• Which feature on a cloning plasmid serves as a region with many unique restriction sites to insert DNA?
• Why is clear labeling of tubes and plates critical in the lab?
• Which statement best describes the purpose of a positive control in a PCR experiment?
• If you observe a sample lane with no bands while ladder shows bands, which is a plausible explanation?
• What is the consequence of inaccurate pipetting in a dilution series?
• Which statement best describes the term genetic engineering?
• Why are negative controls used in transformation experiments?
• Which plasmid feature initiates transcription of the inserted gene?
• In gel electrophoresis, why do DNA fragments separate by size?
• Why is RNase treatment used during DNA isolation?
• What is a common cause of non-specific amplification in PCR?
• Why is loading dye added before loading samples into an agarose gel?
• What substance is used as food for the bacteria, and in what two forms is it found in the lab?
• During gel electrophoresis, what is a consequence of overloading the gel with too much sample?
• LB stands for Lysogeny Broth and is used as what in the lab?
• What was the purpose of the Elution Buffer?
• Which gene on the pARA-R plasmid codes for red fluorescent protein?
• What is the purpose of including both a control group and an experimental group in this transformation experiment?
• In protein purification by chromatography, which property of the protein was exploited to separate it?
• Why are the colonies red on the LB/amp/ara plate but not on the LB/amp plate?
• The typical pH range of running buffers used in DNA gel electrophoresis (TAE/TBE) is approximately
• In the R- tube, which statement is correct about plasmid configurations and gel migration?
• In what circumstances might it be important to use gel electrophoresis to separate and identify plasmids and short linear pieces of DNA?
• In a DNA gel image, if you see a band at the expected size, what does that indicate?
• What is a genetic disease?
• What is the purpose of a DNA ladder in gel electrophoresis?
• After centrifugation, does the eluate containing red fluorescent protein appear brighter or dimmer than the original cell lysate?
• If two plasmids with different antibiotic resistance genes are mixed, how should you handle sorting?
• What is the general purpose of controls in experiments?
• What is the role of arabinose in the experiment?
• Which statement about arabinose presence and AraC function is true?
• What is the natural role of enzymes in bacteria?
• Which term describes a group of identical bacterial cells growing together on a solid medium?
• What are two purposes of using the loading dye in gel electrophoresis?
• What is the purpose of using designated biohazard waste containers for disposing used pipette tips and microcentrifuge tubes?
• Why did E. coli grow on both the P- and P+ sides of the LB plate?
• What does sterile technique entail when handling bacterial colonies from plates?
• Which step is used to increase uptake of plasmid DNA into competent cells during transformation?
• How does a 1:10 dilution differ from a 1:100 dilution?
• If only 1 in 1,000 cells were transformed, what does this imply about the number of cells in a 50 picoliter suspension?
• What is a vector in cloning, and how does it differ from a genetic insert?
• What properties of amino acids contribute to protein folding?
• What characteristic of red fluorescent protein is used to separate it by column chromatography?
• BamHI and HindIII are restriction enzymes. What determines where they cut the DNA?
• Adding human DNA to bacteria makes it possible to make human insulin. What outcome is described?
• During gel run, what indicates the procedure is proceeding correctly?
• What is the order of molecular events that converts a gene into a protein?
• Why is a protein's conformation important for carrying out its function?
• How do you calculate the dilution factor for a two-step dilution with 1:10 and 1:100 steps?
• What color does the reporter protein produced by the plasmid fluoresce?
• What does the presence of multiple bands in the R- lane suggest?
• In PCR, what provides the primer binding sites for DNA amplification?
• In an arabinose-inducible system, what is the role of the araC gene on the plasmid when arabinose is present?
• What is the purpose of an incubator in bacterial culture work?
• Which two diseases are cited as examples of defects in protein production causing complications for an organism?
• In cloning workflows, which statement accurately describes the insert DNA's purpose?
• Why distilled water added to the R- tube in this experiment?
• Based on molecular weights, which dye would you expect to move farthest in an electric field if migration were solely by size?
• The PBAD promoter on the plasmid drives expression of which gene?
• Before ligation, how does gel analysis help ensure the fragment is suitable?
• What is the primary purpose of a no-template (negative) control in a PCR experiment?
• What is the difference between P+ and P- tubes?
• What is the purpose of growing transformed bacteria in the presence of ampicillin?
• Why is it important to avoid mechanical shear during plasmid isolation?
• What is the role of an origin of replication in a plasmid?
• What property of the protein was used to purify out the protein in chromatography column?
• What does the araC gene code for on the pARA-R plasmid?
• Why is it necessary to use very small and exact volumes of reagents in biotechnology?
• What is the usual method of bacterial reproduction?
• In lab practice, what does 'sterile sampling' mean when picking a colony for further study?
• What would the display window show on a P-20 micropipette when set to 6.3 microliters?