QIAEX II gel purification kit - (Oct/11/2007 )

Does some body have an experience of working with the QIAEX II gl purification kit. In this protocol its written that after pellet washing wait until when pellet becomes white. what does it mean pellet is white during drying or wait until pellet becomes white like a powder. I am confused. because i dry my pellet just 15 minutes and did elution but 260/280 ratio is very bad which shows it still have ethanol. does some body can share his experience

If I remember correctly, I didn't get good yield using QIAEX II gel purification kit. My pellet wasn't visible. The kit involves addition of some beads, right? Though some said it's better than other gel purification kit, I didn't really like it.

You can try to ethanol precipitate your product to get a better yield.

Hope this helps.

I really like this kit and very often I am working with it with successful result. I think it gives good yield than usual colums. Now to your qustion. Dry until pellet becomes white means, dry it compleately untill there is no any solution at all. the bed will become really white and if you disturb them it will fall down by inverting the tube. Usually it takes one or one and half hour for complete drying. But I am keeping the tube under a table fan to dry it fast.

yeah you got my question right. Yeah i observed that pellet started to be white but i was afraid that pellet started to be over dry and its yield will be very low or no elution at all. So i should wait it till it become a white like a powder white and then elute the DNA.

I am using QIAEX II gel purification kit frequently. I dry my beads after pelleting under hood with air flow. It usually takes half an hour for drying the pellet i mean visually the pellet turns to white.
All the best for your experiments.

Ya u r right. If you over dry, it wont reduce the yield. I even dried it overnight and never had any problem. Also better to do a second elution if you are not so strict on your concentration. All the best...

Hi,
I remember getting a good yield with this Kit. I prefered it, when I had to gel-purify larger fragements and the yield was quite good.
But I also remember the problem with the white, maybe over-dried pellet, because in my case the yield decreased in a high degree. But If it worked out for all of your guys...

Thanks for the reply. I think i was doing a mistake in drying the pellet. I kept it just for 15 to minutes and when it stared to be white i suspend it ion elution buffer which seems to me was a wrong, because if i now smell my sample there is smell of ethanol in it and thats the cause of failure in ligation i think. Now i will wait till when it will really become white like a powder white rather a wet white.
thanks for the suggestion

hem 230 value should be read too to ensure good purification and good drying.
If your 280 value is high, a thrid wash with binding buffer should be done before washes with ethanol solution.

I checked my sample through nano drop and values are like this 260/280 1.90 and 260/230 values are 1.61 and in the second sample values are 1.81 and 1.34 respectively. I smell my sample and there is clear smell of ethanol there and it means sample is still not pure.