In my opinion, you have degraded RNA and contamination with DNA. Did you digest the samples with DNase?

High molecuar weight bands as seen on your gels are DNA. Good quality RNA can be seen on gels as 2 strong  bands (26S and 18S) . Check out this link for further info:http://www.lifetechnologies.com/hr/en/home/references/ambion-tech-support/rna-isolation/tech-notes/is-your-rna-intact.html

to remove the possibility of contamination of DNA, treat it with DNase. Load on a denaturing agarose gel and check if you can see two bands.. one of 18 S rRNA and the other of 28 S rRNA. The band of 28 S rRNA will be of almost double the intensity of 18 S rRNA.. this can give you some clue about the integrity. 

The size of mammalian ribosomal RNA: 28s is  4.7 kb and 18s is 1.9 kb.  Good quality RNA run out on a 1% agarose gels should  have those 2 bands in equal intensity.  Higher molecular weight bands are DNA contamination.

I too agree that the RNA is contaminated with DNA. (as a band appears near to the well and is around 10 kb).I have not used DNAse-1 to remove the DNA.

Thankyou all for sharing this information and your prompt reply.

A simple way to check for the presence of DNA in an RNA prep is to stain using Acridine Orange dye

DNA will show as green while RNA will be red under UV

The bright fat bands at the top  are DNA band and looks like you might have some degradation of the RNA as well. A simple way to test would be to perform a PCR on a gene fragment spanning an intron. If you have DNA contamination it will show in the size of the band

I agree that uit looks like DNA at the top and degraded RNA in the lower part of the gel. Another way to check is to RNAse the gel. RNA staining should disappear.

Yes, Today i used RNAse to check RNA is there or not in the sample. I have incubated sample for 20min with RNAse and performed electrophoresis. The entire RNA in the lower portion of gel vanished.The 2, 4th and 8th lanes are samples treated with RNase A. In those lanes no RNA is present, but i found a band at the well (may be DNA)

well Did you take the O.D f your sample before runing it on the gel, so that you should be aware of contamination of your sample here is method how to measure the RNA and if it has any contamination ( available at internet ).

Add approx. 15-25 μl (depending on yield) of either DEPC treated TE buffer or water to the RNA pellet.

To a small eppendorf tube, dilute the RNA 1/40 (1.2 μl in 48.8 μl of TE buffer) and add to a microcuvette (path length = 1 cm).

Take absorbance at 260 nm.

The 260/280 ratio should be greater than 1.8. If it is  less than 1.5-1.6 or so,

it means, it is  partially degraded.

Lower ratios also suggest the DNA or thiocyanate contamination.( with trizol method)

The concentration is essentially the equivalent of the OD at 260 nm (in μg/μl). The integrity can be best  seen on the 1% agarose  gel if your rna is pure. You  should use the guanidine  method to isolate  rna .28S , 18S and 5S should be visible on the gel with this method if you concern with its integrity. Your  rna seems to be degraded and contaminated with DNA.

you need to make 2 samples one with RNase treatment and the other without. (you should use DNase during RNA extraction). then run a gel and compare for yourself.  All the best 

Looks like DNA (upper, single, relatively sharp band) and badly degraded RNA (smear at bottom with some blurry bandedness).  I do not see any sign of the 18S and 28S bands which should be strong in an undegraded RNA sample.  The band-like character in the bottom smear may arise because the degradation of the 18S and 28S rRNAs is not completely random but tends to occur at some specific locations.  Your tissue may contain a high level of RNase or your tissue disruption and lysis methods may be insufficient to prevent RNase activity during the extraction.

I agree with the above interpretation.  digest for 10' with DNAse and see if it goes away

Looking at your images, its very easy to conclude that bands are of DNA and RNA has been degraded.. Isolate RNA in highly clean area. wipe yo table well with alcohol and use fresh tips for your RNA work. keep wiping your hands with alcohol in between and carefully do steps where there are chances of RNA degradation. treat yo RNA with DNase to avoid Dna contamination. Integrated RNA give two bands, one corresponds to 28S rRNA and lower one to 18SrRNA in eukaryotic system and in prokaryotic system upper band corresponds to 23SrRNA and 16SrRNA. good luck.

I agree with the above comments with respect to DNA band, RNA degradation, imperative need for extreme care during manipulation, etc.

Additionally I would emphasize that if the spin column + its manual (protocol) is right and correct, you should not have that DNA band there. Either you erroneously omitted the DNase digestion step, or the DNase was inactive or the buffer was wrong or you had so high amount of DNA that your enzyme could not cope with that.

The problem is that DNA and RNA have rather similar chemical behaviour, therefore unless the pH and the salt concentrations are very correct, they prone to contaminate each other's preparation. Many protocols are nice and effective in opening cells, getting rid of metabolites and proteins and others but give you a mixture of RNA/DNA. If you aim a downstream application where the DNA contamination is a danger like qPCR, you must use the DNase treatment, but even then prior to DNase, (or otherwise instead of DNase) I suggest you to do the next:

When you have the nucleic acid preparation possibly containing DNA but free of most proteins and others, precipitate your RNA using Litium chloride (LiCl) with a final concentration of one mole/L or similar. Half an hour room temp. enough, longer or colder does not help much. Do not add ANY alcohols!!! Centrifuge thoroughly and wash the pellet (even if it is not really visible) with 0,5M LiCl at least once. Now you can wash away the remaining droplet of LiCl with 70% EtOH and dry your pellet and do whatever downstream applications you wish to.

LiCl quantitatively precipitates RNA while does not have any effect on DNA without ethanol or iPropanol. These alcohols are in the protocols only for historical reasons, and they only cause problems.

Thank you sir for your valuable suggestions.

I agree with all the replies above. Nowadays, Qubit fluorometric kits are also useful to do the job.