Hi Natalia

Rinsing cuvette in between with ddH2O should be sufficient while measuring DNA samples...

bye

Thanks, Ajay!

I never got it, why should be cuvette (or nanodrop) washed with ethanol, if it precipitates both proteins and nucleic acids?

Just use water, that's the best.

First you clean them with water only and once they are clean you can dry them with acetone and hair drier

why don't u use different cuvettes ?

It is convenient to use plastic cuvettes rather than quartz.. That will work best..

Hi

I agree with Kalaiarasi and David...if one can use different cuvettes (like plastic ones)...it is convenient...but if the lab doesnot have enough funds..it would be difficult.....

Hi, Nathalia

If your spectrophotometer use a large cuvette as 1ml, you just rinse with ddH2O and tap gently in the soft paper the cuvette.

if it is smaller volume you need clean and dry better because the left volume of water can be inerfere in the total volume and dilute your next sample. I recomend to use Qubit (Invitrogen) fluorimeter for better measurement if you are going to use for sequencing or exome studies.

good look

ddI H2O is fine

Natalia,

I use single use cuvettes (UVette from Eppendorf) it is very convenient but you need a biophotometor from Eppendorf. The volumes needed are about 50 ul to 100 ul.

For quartz cuvettes I would rinse them first with water otherwise I would be afraid about fixing DNA, then EtOH 70° to dry them faster.

Dear Natalia,

I can share my own views to you. EtOH is not suitable for rinsing. You just rinse the quartz cuvette 2/3 times with ddH2O and make triplicate for each sample, its average value you have to take. That'll be more error-free.

If you have the facility of Nanodrop, use it due to its more suitability.

Dear Natalia,

Its better to use not more than twice a cuvette. try different cuvettes

Generally nanospectro is used for DNA/RNA measurement and UV-vis spectro for protein measurement but nano facility is not available everywhere. Once can used spectro for DNA quantification by diluting it and u can use one quartz cuvette for diff samples, rinsing with ddH2O only.

Yes i agree with u @ sonam vijay...nano drop measurement is more accurate:)

Never use a plastic or glass cuvette. The reason, there is strong absorption in both the substances in UV region. One can use a good quality quartz cuvette n number of times after washing it properly. DI water, DD water should be fine. Wash it number of times. However, do not trust the protocol just like that. Correct the base line of the UV-Vis using air only. Then put the empty test cuvette in the measurement slot, and take a spectrum till 200 nm. It should give flat plateu. If there is rise from 300 nm, it means DNA is still there. Rinse again.

I agree with Asitikantha Sarma, never a plastic or glass cuvette for UV detection (only quartz cuvette). if you expect a little variation between samples so non rincing needed as remained DNA in the cuvette will be diluted in the next mesurement. To minimize error you can carry out your measurement in dupilcate. At the end of your experience you can rince with ETOH 100% and then with ddH2O.

Dear Natalia,measuring the same sample several times, you will find the accuracy of these measurements is quite limited. Therefore I would not go crazy about normalizing and double-or triple checking. If your application requires EXACT amounts of DNA, you will have to use special procedure anyway:THEN (and only then) I recommend using two different spectrometers and making dilution curves, measure in triplicates, average everything. If you just care about the approximate amount (99% of applications) for a digest, a ligation, or just to know the yield of your maxi prep, just go with the very first suggestion (Harald). However I usually still rinse once with DDI Water (even if its obviously not really necessary), just feels like the right thing to do. EtOH is not necessary.

For quartz cuvettes you should rinse them first with Aceton to settle the DNA, for about one min then EtOH 70% to remove them faster.