2
votes
1answer
32 views

What causes skewed ladder bands on an agarose gel?

I frequently ran into an issue where the bands of my ladder become skewed. What causes this? Here's an example: 0.7% agarose gel, 100V, 60 minutes. Same problem occurs with 1%. I loaded 10 ul of a 20 ...
6
votes
1answer
100 views

DNA extraction from agarose gel

Because DNA is soluble in water, is it possible to extract PCR product by dissolving excised gel containing the DNA band of desired length in water, mashing the gel piece with a pestle, centrifuging ...
7
votes
3answers
158 views

Possible reasons for DNA getting stuck in well

I am in the process of Library preparation for Illumina MI-Seq using mtDNA. Using NEB Hotstart LongAmp Polymerase, I was able to obtain upto 10kb amplicons of mtDNA. However, when I switched to a ...
2
votes
2answers
110 views

Single stranded DNA in gel electrophoresis

From http://www.nfstc.org/pdi/Subject05/pdi_s05_m01_01.htm : ... The separation medium contains a denaturant in order that the electrophoresis is conducted on single-stranded DNA fragments. ...
7
votes
2answers
118 views

What causes skewed lanes in a DNA gel electrophoresis experiment?

In gel electrophoresis, what causes effects like these (see collumn 11 in the first one, an collumn 6 in the second). ? (These images were samples that I took from an online activity we did for ...
5
votes
2answers
1k views

How do we know that everybody's DNA fingerprint is unique?

How do we know that everybody's DNA fingerprint is unique? I know, I know, everybody's DNA is unique. But when we do DNA fingerprinting, we're looking at very specific regions of high variability. ...
1
vote
2answers
327 views

Gel electrophoresis after RNAse treatment

I do not understand how to solve this question. I know that RNAse will cut smaller pieces of RNA. The answer given is A
2
votes
1answer
95 views

Should the length of the electrodes in the electrophoresis chamber be proportional to chamber's size?

I am trying to build a small horizontal electrophoresis chamber from scratch. I want to use it for comet assay and I will be using only 1 slide, so it's going to be about 3cm wide, 10cm long and 4cm ...
2
votes
3answers
2k views

Separating DNA Fragments by Gel Electrophoresis. Are all the strands for one size the same?

My apologies if my question is too basic, and please point me to a more appropriate forum. I am reading the textbook "Essential Cell Biology" by Alberts et al, and am consulting other sources as ...
3
votes
1answer
179 views

What is the DNA/protein charge ratio?

To study DNA-protein interaction, I want to do a DNA retardation test by mixing the protein with DNA and afterwarts loading it on an agarose gel to see if the DNA migrates slower. I've found some ...
12
votes
3answers
9k views

How many agarose gel bands are typical for circularised DNA

I am aware that circular DNA can be both relaxed and super coiled. However when running an agarose gel of the circular plasmid along with singly digested plasmid with BamHI and HindIII, I see 1 band ...