Dear Harvey Based on the experimental history you provided I would try two quick things in order to obtain additional dimensions for your condition. (1) set up your best consensus condition against an additive screen (e.g. From Hampton). (2) I would repeat your last pH vs precipitant grid against different starting protein concentrations. You can conveniently play with different drop ratios to screen for that.
Best regards Savvas On 21 Feb 2011, at 03:29, Harvey Rodriguez <h.rodriguez.x...@gmail.com> wrote: > Dear CCP4BBers, > > Recently I got a crystal which appeared in the condition 2.1M DL-Malic Acid, > pH 7.0. The crystal looks like a dumbbell but was composed of a cluster of > very thin needles as shown in the picture. The crystal can be repeated but > the diffraction is poor. I have tried the grid optimization by pH and salt > concentration gradients, however there was no improvement in either the shape > or the quality of the crystal. Does anyone have some experiences in > optimizing this kind of crystals? Any suggestion is appreciated! > > Harvey > <dumbbell crystals.jpg>