12 replies to this topic

[lucilius]

Hallo all,

when I do a DNA extraction I always notice some sort of slime formation at the moment I add 1 buffer and ethanol to the sample.
I see a white precipitate and the slime formation at that point.
I was wondering what this slime is? Is this the DNA?

[El Crazy Xabi]

Could you be more specific? There are heaps of DNA extraction protocols

[lucilius]

El Crazy Xabi, on 13 March 2013 - 06:38 PM, said:

Could you be more specific? There are heaps of DNA extraction protocols

its a qiagen extraction protocol.
You can find the protocol here: http://www.qiagen.co...}&lang=en&ver=1
Its on page 29, step 3.
Its when you add the ethanol and buffer AL you get the slime.

[leelee]

It tells you what it is on the top of page 30....

[lucilius]

leelee, on 14 March 2013 - 02:02 AM, said:

It tells you what it is on the top of page 30....

No

the white precipitate is something different.
I see that too.
Its not that !

Its a clear (transparant) slimy thing.

[hobglobin]

from what organism are the tissues or samples?

[lucilius]

hobglobin, on 14 March 2013 - 10:13 AM, said:

from what organism are the tissues or samples?

eukaryotic organisms.
unicellular organisms.

[pcrman]

Quote

A white precipitate may form on addition of Buffer AL and ethanol. This precipitate
does not interfere with the DNeasy procedure. Some tissue types (e.g., spleen,
lung) may form a gelatinous lysate after addition of Buffer AL and ethanol. In this
case, vigorously shaking or vortexing the preparation is recommended.

I think what you saw is just DNA and is more apparent when DNA concentration is high.

[lucilius]

pcrman, on 14 March 2013 - 10:21 AM, said:

Quote

A white precipitate may form on addition of Buffer AL and ethanol. This precipitate
does not interfere with the DNeasy procedure. Some tissue types (e.g., spleen,
lung) may form a gelatinous lysate after addition of Buffer AL and ethanol. In this
case, vigorously shaking or vortexing the preparation is recommended.

I think what you saw is just DNA and is more apparent when DNA concentration is high.

Thats what I think too....

But is there anything known about this? I have seen this before, written down, in for example the DNA extraction of kiwi, but how come DNA forms this white slime?

Altough... the DNA concentration is not that high when I do the extraction.

Edited by lucilius, 14 March 2013 - 10:26 AM.

[pcrman]

You can see DNA even do it in your kitchen http://kitchenpantry...ist.com/?p=2244

[leelee]

lucilius, on 14 March 2013 - 09:16 AM, said:

leelee, on 14 March 2013 - 02:02 AM, said:

It tells you what it is on the top of page 30....

No

the white precipitate is something different.
I see that too.
Its not that !

Its a clear (transparant) slimy thing.

They mention both a white precipitate AND a gelatinous lysate....

But anyway, could it be just due to the fact of mixing two different liquids together of different salt conc./densities/etc? For example, when you add an enzyme to a solution, you can see a "slime" (due to the glycerol in the buffer) until you've mixed it properly. It could be something like that?

[lucilius]

leelee, on 14 March 2013 - 05:12 PM, said:

lucilius, on 14 March 2013 - 09:16 AM, said:

leelee, on 14 March 2013 - 02:02 AM, said:

It tells you what it is on the top of page 30....

No

the white precipitate is something different.
I see that too.
Its not that !

Its a clear (transparant) slimy thing.

They mention both a white precipitate AND a gelatinous lysate....

But anyway, could it be just due to the fact of mixing two different liquids together of different salt conc./densities/etc? For example, when you add an enzyme to a solution, you can see a "slime" (due to the glycerol in the buffer) until you've mixed it properly. It could be something like that?

It could be yes.
I dont know.
I think its the DNA , but not sure why it forms this slime...

[2xzwei]

Lysing your cells sets free its components, membrane macromolecules i.e. glycoproteins which are able to build intermolecular networks causing the formation of gel-like liquid or so-called "slime".