12 replies to this topic

[sxh999]

Hi everyone,

I did gel electrophoresis after DNA extraction. However, there was gel smear as shown in the attached image. Could anybody help me to analyze the possible reason?

My sample is water full of bacteria flocs, and I used DNeasy Kit to do DNA extraction and followed the procedures in the protocol. I am sure the process had no problems.

Do I need to use another kind of Kit for DNA extraction? Thank you very much..

Holly

[sxh999]

I  was not permitted to upload my gel image....

[pito]

sxh999, on 19 February 2011 - 10:26 AM, said:

I  was not permitted to upload my gel image....

How you mean? Your lab didnt allow it? or you got an error on this website?

What was the error if you had one?

Maybe the file was too big?
With a picture its always easier to get help.

[seanspotatobusiness]

pito, on 19 February 2011 - 10:27 AM, said:

sxh999, on 19 February 2011 - 10:26 AM, said:

I  was not permitted to upload my gel image....

How you mean? Your lab didnt allow it? or you got an error on this website?

What was the error if you had one?

Maybe the file was too big?
With a picture its always easier to get help.

Maybe it's because they're a new poster. Newcomers often have such restrictions on forums until their post-count hits a certain number.

[sxh999]

Thank you all for your reply.

I meant I have problem to attach the image of my Gel in this website.

I will try to poster the image here, so you can have a look and help me to analyze. thank you very much.

[pito]

sxh999, on 20 February 2011 - 10:37 AM, said:

Thank you all for your reply.

I meant I have problem to attach the image of my Gel in this website.

I will try to poster the image here, so you can have a look and help me to analyze. thank you very much.

If it doesnt work, you can always send it to me in a private message so that I can upload it.

[sxh999]

Thank you all for your kind help and suggestion.

I just knew how to upload my image, as shown below: I will very appreciate if you can help me to find the reasons of Smear.

PS: my sample is activated sludge(there are many suspended flocs), my DNA extraction Kit is "DNeasy Kit".

when run the gel:
For the ladder: 1uL ladder+3uL water+1uL dye.
For my sample: 2uL sample+2uL water+1uL dye.

[Ameya P]

Is it just me or cant anyone see wats in the pic?

Sxh, another upload please...

And you have stained the gel right?

[pito]

gt_ameya, on 22 February 2011 - 09:43 PM, said:

Is it just me or cant anyone see wats in the pic?

Sxh, another upload please...

And you have stained the gel right?

http://www.freeimage...?ac80da4f48.jpg

This is the gel.
I dont know why it doesnt work when shx999 posts it.

Attached Thumbnails

• 

Edited by pito, 23 February 2011 - 05:52 AM.

[Ameya P]

Although, there is smearing, there are some bands which you see on top of the gel in some cases. So, there is DNA.

What do u need the DNA for? Any PCR should work with what you have now...

[pito]

There is a lot of smear. It looks like a gel that I prepare when I want a smear.. lol

What protocol did you use? Did you use a beatshaker?


And did you check the sticky on this forum about how to prevent smearing

gt_ameya is also riht that you, even with the smear, still have some DNA bands.

[phage434]

This is entirely typical of genomic DNA.  Why do expect bands?

[sxh999]

Thanks to all your reply.

yes, there was DNA and I did PCR with those DNA, there was some non-specific bands in the PCR Gel.


But I used another DNA extraction Kit (Powersoil Kit) and repeated DNA extraction again, it seemed better than before (little smear).

I am really confused that you can not see my pictures in attachment. What is the format of your picture uploaded? jpg? Thanks to all.