Low yield after gel extraction - (Nov/02/2006 )
Hi all! Thanks for the suggestions! Well, I'm using 30-50ul Water or Buffer EB to elute my DNA. Have tried both solutions and both still gave a conc of 5 ng/ul. There was no peak at the 230 mark when using nanodrop as well.
I did heat my water beforehand. What baffles me is some people use the Qiaquick kit and have no problems while others face many problems when using the kit. I hope it has nothing to do with my technique as one of my lab officers have tried and she too had a low yield.
Does a low yield after gel extraction affect the subsequent sequencing?
low yeilds = small quantities of DNA = weak signal = shorter sequence reads (or worst yet a signal too week to read)
I don't know at what quantities does the DNA become too little to sequence (ie signal so week it is essentially drowned in noice). I have never tried to find out.
Also note, the silicon columns do have an expiry date. The recovery rate starts to drop around and after that date. I am told (don't know if this is true) that the Qiagen column is essentially dead 1yr after the column has expired.
We had the same problem in our lab and it was gone, after a new set of columns arrived. We had purchased the large size somewhat earlier and half of the columns ran out of date! So trying fresh columns may be a good idea!