How does gel electrophoresis seperate DNA?

The DNA from PCR is placed into wells of agarose gel and a buffer solution is poured over it. An electrical current is passed through the gel due to the conduction of the buffer solution. The DNA fragments move towards the positive elctrode because they are negatively charged. Shorter DNA fragments travel further through the gel as they move faster, seperating the DNA by its length.

Holly D. GCSE Biology tutor, A Level Biology tutor, GCSE Chemistry tu...

5 months ago

Answered by Holly, who has applied to tutor A Level Biology with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist


£20 /hr

Josh J.

Degree: Biomedical Science (Bachelors) - Sheffield University

Subjects offered: Biology, Geography


“I am a confident and diligent person who enjoys communicating and working within a team to find the best possible outcome for the student. I have a strong background in tutoring, and have worked within voluntary roles which aid those ...”

£20 /hr

Jonathan T.

Degree: Biological Sciences (with placement) (Bachelors) - Durham University

Subjects offered: Biology, Maths+ 1 more


“About me:I am a Biology student studying at Durham University but currently working in Cambridge on my year in Industry. I love all things Science and have a huge passion for sharing my knowledge in the field and developing others ...”

£20 /hr

Charlotte C.

Degree: Biological Sciences (Masters) - Durham University

Subjects offered: Biology


“Hi! If you're looking at my profile, you're probably finding Biology a bit tricky and just need a hand understanding some of the (admittedly complicated!) parts of the course. You'll be relieved to hear that I was once in your shoes -...”

About the author

£20 /hr

Holly D.

Degree: Physiotherapy (Bachelors) - Nottingham University

Subjects offered: Biology, Psychology+ 1 more


“I am a first year physiotherapy student at Nottingham University. I chose this degree as I love working with people and I’m fascinated with how the human body works - I hope this comes across during my tutorials! I used mytutor during...”

MyTutor guarantee

You may also like...

Posts by Holly

How does gel electrophoresis seperate DNA?

What happens when some alkali is added to a buffer solution?

Other A Level Biology questions

Explain how water is re-absorbed in the kidney

How does a cell produce energy?

Why is the polymerase chain reaction important and how does it work?

How is the structure of alveoli suitably adapted for efficient gas exchange?

View A Level Biology tutors


We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss