You can try NanoDrop

Here is the website link

http://www.nanodrop.com

If you want to know quantity then use Qubit RNA assays (HS can go as low as 5ng), unfortunately nanodrop gives inaccurate quantification. However, nanodrop can be used to gauge quality, but best is to use Agilent Bioanalyzer RNA chips that'll give you RIN (RNA Integrity Number) quality.

regards

Perhaps looking for , bioanalyser,agilent or experion biorad or caliper perkin elmer wil help in finding a good alternative for the spec. Determination of the quality of your samples

NanoDrop spectrophotometer need only 1uL

Nanodrop and Qubit RNA assays are good choice but always check it in gel......

I do agree with Edmundo in the perception that Nanodrop overstimates the amount of nucleic acids. In our hands, bioanalyzer understimates the amount of RNA. We have very nice results with quantifications by Qubit when using limited material.

If you want to quantify and check RNA integrity, you should used Bionalayzer.

Dear chandra,,,

First u check the quality of RNA u isolated... may be it is not good enough and less in amount.. check in 1.2- 1.3 % agarose gel... dilute it in DEPC water and use nano drop or Bio photometer for the quantification.. all wl give u the same result.. if ur RNA is not degraded...(before checking worm it in 60-65 degree for 2-5 mint in water bath.... may be this step u skip).. before doing all these thing first u check ur isolation procedure....

all the best...

Greater than 50ng/ul, the nanodrop is good for quantification, less than 50ng/ul a ribogreen assay will be better for quantification. Bioanalyzer chip assays give a good measure of RNA integrity and possible genomic contaminations.

I guess using a nanodrop will do the job for you with as little as 1 - 2 ul of sample..

Nanodrop should be fine even though it can overestimate sometime. you may chose Bioanalyzer if available. to confirm the quality of your mRNA you may look for its integrity and then you should run formaldehyde gel electrophoresis.

Bioanalyzer will give you both the purity , quantity and quality (in terms of integrity).

cheapest method if no access to nano-drop. Densitometry

http://www.thermoscientificbio.com/nucleic-acid-electrophoresis/riboruler-high-range-rna-ladder/

Nanodrop spectrophotometer.

The NanoPhotometer is better than the Nanodrop in many ways. Most importantly, the NanoPhotometer has the best technology to measure small volumes (allowing a minimum of 0.3 uL). No reconditioning or recalibration is necessary with the NanoPhotometer (high quality inert quartz and no path length drift!) which is not the case with the Nanodrop and researchers tend to forget about things like that.

Microvolume UV-Vis is a great way to quantify your RNA. The perception of NanoDrop over-estimating the concentration may be due to sample quality (or issues with calibration or broken sample columns). All nucleic acids and some contaminants will contribute to the absorbance at 260nm and therefore the concentration calculation. A sample that is giving you higher than expected values is likely to benefit from a clean up. You can get a specific quantification of your sample using fluorometric methods which will bind specifically to long RNA in your sample. Downside is you need to buy the assay and create a standard curve.

When you look at purity ratios using absorbance you can get an estimate of the unwanted organic compounds such as trizol, phenol guanadine HCl etc when using the 260/230 and contaminating protein using the 260/280 ratio.

In order to get an all round picture of contamination of your sample, it is good practise to look at both the absorbance and fluorescence profiles of your sample. In broad terms, you should compare e.g the fluorescence of your RNA sample to it's concentration gained by microvolume absorbance. The difference between the 2 values is a guide to how much contamination of "other" nucleic acids are in the sample There are some assumptions you have to make about fluorescence for this to hold true - such as pipetting accuracy, how appropriate the standards are to your samples etc. and that the absorbance peak at 260nm is primarily due to nucleic acid, but it generally holds well that if there is a big delta between the values then the sample is "less good"

There is a great tech note on this here

https://www.denovix.com/pdf/156-Absorbance-and-Fluorescence-Quantification.pdf

or a nice infographic

https://www.denovix.com/absorbance-fluorescence-quantification-infographic/

Andy