I purchased a signed photo of Nirvana on eBay including all three authographs of the band members including Kurt Cobain, Dave Grohl and Krist Novoselic. I tried several attempts to have the photo authenticated from psa/dna, with the results not genuine. I then asked several collectors that only deal with nirvana memobelia and the results were always not genuine. I contacted the seller and he explained that unfortunately I cannot do anything.