DNA extraction with expired kit? - (Aug/27/2009 )

Hello, I'm relatively new to lab work, but I need some help. I'm trying to isolate DNA from mononuclear cell lysates that were partially prepared by someone else using the 'illustra blood genomicPrep Midi Flow kit'...the cells were isolated with 8ml of whole blood using Ficoll, and then the lysate was prepared with the kit (Lysis solution and Proteinase were added to the pellet) and stored, all approximately a year ago. So, my job is to continue from this step. The kit in the lab expired in September 2008, but I tried to isolate DNA from a spare sample using the kit anyway- sadly, I couldn't detect any DNA in the final elution after measuring it in the spectrophotometer. Do you think the lack of yield could result from the degradation of the columns? I know they were technically expired, but obviously companies put the most conservative estimate as their "expiration" date, so I thought it was worth a shot. Tech Support at GE said that the buffers should be okay, but they didn't address the issue of the columns. I don't think I messed up the protocol because it's incredibly straightforward.

most columns are just silica gel. They should be ok.

The problem was most likely the old samples.