D1.1 Gel Electrophoresis
No description yet. This curated deck is ready for daily study.
Card preview (13)
Purpose of gel electrophoresis?
Separate DNA fragments by size/charge.
Why does DNA move in the gel?
Negatively charged phosphate backbone → moves toward positive electrode.
What type of gel is used?
Agarose (jelly-like matrix).
What forces affect movement?
(a) Electrical charge, (b) Size of fragment (smaller = faster).
Why do small DNA fragments move faster?
They slip more easily through pores in the gel.
What is a DNA ladder/marker?
Fragments of known size → used as a reference.
Why add loading dye?
Makes DNA visible + heavy so it sinks.
What is a well?
Small holes in the gel where DNA samples are loaded.
How are DNA fragments visualized?
Stains: ethidium bromide (fluoresces under UV) or methylene blue.
Why use buffer solution?
Conducts electricity across the gel.
Which bands are furthest from the wells?
The smallest DNA fragments.
What happens after electrophoresis?
Bands of interest can be cut out → DNA extracted → sequencing.
What do bands represent?
Groups of DNA molecules of the same size.