The protein that I am working on gives several initial hits which are needles. And at random, I picked the needles from a condition (0.2 M cacl2, 0.1 M HEPES pH 7.5 & 28% PEG 400) and seeded into another screen where I added 1µl protein + 1µl reservoir solution + 0.3 µl seed stock. I prepared the seed stock fresh by adding 36 µl of the reservoir solution to preexisting 2µl drop. 

One of the conditions from the seeded screen gave me a hit that looks really promising ( see attached). I am sort of positive that these crystals are protein as they are UV active. 

I tried to reproduce these but with needles from another condition which actually look much nicer than the seeds i used to produce these crystals. However, I failed to do so. 

While i understand that seed quality is important, I find it interesting that the crystals do not reproduce with similar or better looking seeds. Is it common that the seeds absolutely need to be from the same condition to reproduce hits ?

thanks for any suggestions 

Mahesh