ATI TEAS (Test of Essential Academic Skills) Version 7ScienceHard
A technician is performing a genetic analysis and needs to separate DNA fragments based on their size. Which laboratory technique would be most appropriate for this purpose?
- AELISA (Enzyme-Linked Immunosorbent Assay)
- BGel electrophoresis
- CSpectrophotometry
- DPCR (Polymerase Chain Reaction)
Show answer & explanationAnswer & explanation
Correct answer: B. Gel electrophoresis
Gel electrophoresis is the standard laboratory technique used to separate DNA fragments (or RNA or proteins) based on their size and charge. Smaller fragments migrate faster and further through the gel matrix.
Why the other options are wrong
- A. ELISA is an immunological assay used to detect and quantify antibodies or antigens in a sample.
- C. Spectrophotometry measures the absorbance or transmittance of light through a sample to quantify substances, not separate fragments by size.
- D. PCR is used to amplify specific DNA sequences, not to separate fragments by size.
Gel Electrophoresis
A laboratory technique used to separate DNA, RNA, or protein molecules based on their size and electrical charge.
- Molecules migrate through a gel matrix.
- Smaller molecules move faster and further.
- Used for DNA fingerprinting, gene cloning, and diagnostic purposes.
Memory trick: Gel electrophoresis is like a 'gel race' for DNA fragments, smaller ones win.