Which step of the organic DNA extraction method involves lysis of white blood cells?

• A) DNA precipitation
• B) Lysis of red blood cells
• C) Digestion step
• D) Phase separation step

What is the purpose of the stacking gel in polyacrylamide gel electrophoresis (PAGE)?

• A) Enhance conductivity
• B) Provide a reference for fragment size
• C) Improve resolution
• D) Separate DNA fragments

How should reagents be stored while preparing liquid reagents?

• A) In-sterile containers
• B) In plastic bags
• C) In open containers
• D) In non-sterile containers

What role does EDTA play in DNA extraction?

• A) Metal ion chelation
• B) Protein digestion
• C) DNA denaturation
• D) Cell lysis

Which of the following is a common method for cell lysis during DNA extraction?

• A) Centrifugation
• B) Enzymatic digestion
• C) Gel electrophoresis
• D) PCR amplification

What is the purpose of adding chloroform to the sample?

• A) To remove the RNA from the sample
• B) To break the RNA into smaller fragments
• C) To remove impurities from the sample
• D) To extract the RNA from the sample

In DNA extraction, what is the purpose of adding a chaotropic agent such as guanidine isothiocyanate?

• A) Protein denaturation
• B) Cell lysis
• C) DNA precipitation
• D) RNA stabilization

In gel electrophoresis, which parameter is commonly used to estimate the size of nucleic acid fragments?

• A) Buffer concentration
• B) Voltage
• C) Migration distance
• D) Gel concentration

What is the purpose of using a spectrophotometer during DNA extraction?

• A) Measure DNA concentration
• B) Enhance enzyme activity
• C) Promote cell lysis
• D) Amplify DNA fragments

What is the ideal A260/280 ratio for good-quality DNA?

• A) ~1.8
• B) ~1.6
• C) ~1.7
• D) ~2.0

What does an A260/A230 ratio below 1.8 indicate in nucleic acid samples?

• A) Presence of proteins or phenol contamination
• B) High purity
• C) Low concentration
• D) RNA contamination

How does the migration of larger DNA fragments compare to smaller ones in gel electrophoresis?

• A) Smaller fragments migrate faster
• B) Larger fragments migrate faster
• C) Both migrate at the same rate
• D) Migration depends on the buffer composition

What type of agarose gel should be used for DNA quantification?

• A) 1% agarose gel
• B) 2% agarose gel
• C) 0.8% agarose gel
• D) 0.2% agarose gel

When preparing a stock solution, which factor is crucial for accuracy?

• A) Temperature of the solvent
• B) Precision in measuring the solute
• C) Time taken for preparation
• D) Volume of the solution

Which electrode is typically connected to the negative terminal in gel electrophoresis?

• A) Neutral electrode
• B) Ground
• C) Cathode
• D) Anode

How is nucleic acid concentration typically expressed based on spectrophotometric readings?

• A) Micrograms per milliliter (μg/mL)
• B) Absorbance units
• C) Optical density
• D) Molarity

When preparing a working solution, what is the effect of using an incorrect volume of the stock solution?

• A) Increased accuracy
• B) Decreased stability
• C) Improved concentration
• D) Altered final concentration of the working solution

How should Ethidium Bromide be stored?

• A) In the refrigerator
• B) None of these
• C) At room temperature
• D) In the freezer

What term describes the process of gradually adding a solution to another while stirring to achieve a desired concentration?

• A) Distillation
• B) Titration
• C) Precipitation
• D) Filtration

What is the ratio of Phenol chloroform isoamly alchol in Phase Separation step of Protein Extraction?

• A) 25:24:25
• B) 25:24:0
• C) 25:24:23
• D) 25:24:1