Search found 15 matches

by Daniel Tillett
Wed Aug 24, 2005 10:55 am
Forum: Molecular Biology
Topic: mtDNA isolation
Replies: 4
Views: 3478

Mitochondria DNA is circular. How it runs on a agarose gel will depend on a number of factors: 1. Agarose % 2. Presence or absence of EtBr 3. Level of supercoiling of the DNA So the simple answer is no. If you want to size your mitochondrial DNA digest with a couple of different RE and add up the ba...
by Daniel Tillett
Tue Aug 23, 2005 11:17 pm
Forum: Molecular Biology
Topic: why only L-amino acids?
Replies: 3
Views: 13292

From memory we have enzyme able to degrade D-amino acids. Also some natural peptides (small proteins) contain D-amino acids so like everything in nature every rule has an exception :)

Daniel

Longer automated DNA sequencing reads
by Daniel Tillett
Tue Aug 23, 2005 11:13 pm
Forum: Molecular Biology
Topic: mtDNA isolation
Replies: 4
Views: 3478

I don't want to be harsh, but you do realise that mitochondria do vary in size depending on the organism. To answer your question about the colour of the mitochondrial DNA, no it should not vary in colour depending on the organism (all pure DNA is colourless). However, if your DNA is contaminated wi...
by Daniel Tillett
Tue Aug 23, 2005 11:08 pm
Forum: Molecular Biology
Topic: Centrifugation query
Replies: 13
Views: 10322

I don't that you would be able to in practice separate two 1,000,000 bp DNA strands that differ by 20 bp as that is only 0.002% difference in length!

Daniel

Higher quality DNA sequencing
by Daniel Tillett
Tue Aug 23, 2005 12:19 pm
Forum: Molecular Biology
Topic: Centrifugation query
Replies: 13
Views: 10322

There are many ways of accomplishing what you want. 1. Do a native Southern (ie don't denature your DNA during transfer to the membrane. RNaseH treat then probe with a labelled oligos that can differentiate bi from unidirectional replication. 2. Capture your DNA using biotin labelled oligos after RN...
by Daniel Tillett
Mon Aug 22, 2005 10:26 pm
Forum: Molecular Biology
Topic: Centrifugation query
Replies: 13
Views: 10322

Can you tell us more about why you need to separate the two DNA- the more details the better? There are a number of ways of doing this and some hard and some are relatively simple. Without knowing what you are trying to accomplish it is impossible to advise what is the best approach to take. Daniel ...
by Daniel Tillett
Mon Aug 22, 2005 2:49 pm
Forum: Molecular Biology
Topic: Centrifugation query
Replies: 13
Views: 10322

The simple answer is no. Is this just a hypothetical question? If not there are other techniques that would allow you to separate them.

Daniel

Improved plasmid DNA sequencing
by Daniel Tillett
Fri Aug 19, 2005 1:45 pm
Forum: Molecular Biology
Topic: RNA as genetic material
Replies: 9
Views: 30487

An RNA genome can be an advantage as it can speed up the process of getting your genes translated into proteins. By having an RNA genome these viruses can avoid the initial DNA to RNA transcription step.

Daniel

Improved automated DNA sequencing
by Daniel Tillett
Fri Aug 19, 2005 1:22 pm
Forum: Molecular Biology
Topic: Assessment of dialysis - How?
Replies: 6
Views: 3844

You could try using a DNA electroporator unit. I did this once to measure low levels of salt in a sample. Just make up a standard curve using a known concentration of salt and compare the time constants between your sample and the known standard. Just don't use too high a concentration of salt Danie...
by Daniel Tillett
Wed Aug 03, 2005 11:44 pm
Forum: Molecular Biology
Topic: Centrifuge PCR microplates
Replies: 1
Views: 1996

I don't think I have ever seen a small and cheap centrifuge that can do this. You could try just dropping the plates from a short height onto the bench. A couple of drops shound get the liquid to the bottom.

Daniel

Improved automated DNA sequencing
by Daniel Tillett
Wed Aug 03, 2005 11:40 pm
Forum: Molecular Biology
Topic: Plasmid PCR
Replies: 2
Views: 3558

It can help if you denature the plasmid before doing the PCR. If you do manual hot starts then denature the plasmid by heating the reaction to 98C for 3 min before adding the Taq enzyme.

Daniel

DNA sequencing software
by Daniel Tillett
Sat Jul 30, 2005 12:30 pm
Forum: Molecular Biology
Topic: agarose gel
Replies: 8
Views: 11872

2. Mass spec is easier if you know the genome from which the protein came.