Hi Zuzana,

when you have low DNA concentrations I think the Qubit is more accurate than the Nanodrop and very often the measurement from the Nanodrop is higher than from the Qubit. You might check out this article: Comparison ofDeNovix, NanoDropandQubit for DNA quantification and impurity detection of bacterial DNA extracts - you can easly find the PDF.

Regarding the low concetration - I assume you are isolation DNA from the hair root and not from the shaft?

Maybe you can provide some additional information about your protocol.

I have one advice already - if you have really low DNA concentration you can use glycogen ( concentration: 0.05-1 µg/μL) for precipitation as this increase the efficiency of the prrecipitation process.

Hello Dörthe , thank you for answer and add next information

I assume you are isolation DNA from the hair root - YES

We use 50 hairs root per sample, the resulting eluate has a volume of 100 µl. Lysis - per sample 200 µl of lysis buffer T1 + 25 µl of proteinase K - incubation for 90 min at 56 °C, on a shaker

2) Continuation on EpMotion: - Binding to magnetic beads - 3x washing – M3 buffer, MB4 buffer, 80% ethanol - Dissolution in elution buffer

the second method - using a commercial kit: NucleoSpin Tissue kit (Macherey-Nagel, Germany, iBiotech.cz Ltd., Czech Republic) according to the manufacturer's instruction.

Hi Zuzana,

have you ever checked your DNA on a gel by gel electrophoresis?

I would do this in any case because than you will see if you have intact genomic DNA (degraded DNA can impact measurement of your DNA concentration and very likely will interfere with your downstream applications (you should see a high molecular band and no or only a little smear).

You can also roughly estimate how much DNA you have in your sample by comparing it to your ladder (needs some experience).

I would also advice to try a more "traditional" method of DNA isolation with DTT in the buffer and a phenol chloroform extraction followed by precipitation with sodium acetate and isopropanole - you can get high quality DNA from this method and I think you should get a relative large amount of DNA from 20-30 hairs (at least for human hair, but I think horse hair should be similar). You can find a nice protocol for hair in the paper "A Simple Method of Genomic DNA Extraction from Human Samples for PCR-RFLP Analysis" Article A simple method of genomic DNA extraction from human samples...

I would do this in parallel to your other methods and see what works best (and I think you should get enough DNA so that you not need glykogen as a carrier - however if you want you can still try this).

I hope this helps

KR Dörthe

Hello Hello Dörthe, thank you for your advice

Thank you Edmund