Dear Chen,
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  <div>It looks like you have a unit cell with two relatively short axes and one long one - and some disorder. I have experienced a few examples of this with virus fibre proteins (adenovirus fibre and T4 short tail fibre). For the short tail fibre we also obtained images in which some lines of spots showed nice separation but others less so.</div>
  <div>You should try and mount the crystals with the long axis roughly parallel to the rotation axis to avoid overlaps. If you screen several (or many) crystals, you may find one with less disorder. In any case, collect complete datasets of the best ones and try to solve the structure, you may get lucky like we did.</div>
  <div><br /></div>
  <div>Greetings,</div>
  <div><br /></div>
  <div>Mark</div>
  <div><br /></div>
  <div><br /></div>
  <div><br /></div>
  <div>Quoting chen c:<br /> <br />
&gt; I attached two diffraction images of my crystal, of which one seems normal<br />
&gt; as protein crystal usually do, while the other one looks very strange ,with<br />
&gt; very continuous lines on the image.<br />
&gt;<br />
&gt; In fact, of the 180 crystal images diffracted by my crystal, there is a<br />
&gt; tendency between those two.<br />
&gt;<br />
&gt; I had thought that my crystal is a combination of many two-dimensional<br />
&gt; crystals, between wich there are translational or rotational translocations,<br />
&gt; namely resulting in a lack of translational symmetry in the third axes. As a<br />
&gt; result of this, when I tried to index them using HKL2000, one of the cell<br />
&gt; parameter is merely several angstroms.<br />
&gt;<br />
&gt; However, of the several data sets from different crystals, one data set is<br />
&gt; sucessfully indexed by the assistant professor of my laboratory and<br />
&gt; currently submitted to the operation of Molucular Replacement.<br />
&gt;<br />
&gt; This confused me a lot. Is what I thought wrong? Or is the very crystal that<br />
&gt; was indexed a special one?<br />
&gt;<br />
&gt; Thanks all<br />
&gt;<br />
&gt; chen<br />
&gt;<br /> 
    <p><!--begin_signature-->Mark J van Raaij<br />
Laboratorio M-4<br />
Dpto de Estructura de Macromoléculas<br />
Centro Nacional de Biotecnología - CSIC<br />
c/Darwin 3, Campus Cantoblanco<br />
28049 Madrid<br />
tel. 91 585 4616<br />
email: <a href="/cgi-bin/wa-jisc.exe?LOGON=A3%3Dind1011%26L%3DCCP4BB%26E%3Dquoted-printable%26P%3D22247087%26B%3D--%253D_5mqpbly1w79i%26T%3Dtext%252Fhtml%3B%2520charset%3DUTF-8%26pending%3D" target="_parent" >[log in to unmask]</a><!--end_signature--></p> 
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