Laboratory Communications in Acta Crystallographica Section F

EMBL Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany, and PO Box 6395, Lawrenceville, NJ 08648-0395, USA The last year has seen a number of enhancements to our still very young journal, Acta Cryst. F. There was, for instance, the introduction of a tool for creating interactive figures (Einspahr & Guss, 2008b) which can then be included in journal articles. The first Acta Cryst. F paper with such an enhanced figure was published by Mueller-Dieckmann et al. (2008). Also introduced was the ability to upload an mmCIF file (obtained upon depositing coordinate and structure-factor amplitude files with the PDB, for example) and create experimental details tables (or even a complete article) for publication (Einspahr & Weiss, 2008). We have also invited the NMR community to publish structures in Acta Cryst. F and devised an updated set of standards for this purpose (Einspahr & Guss, 2008a). More information on these standards can be found at http://journals.iucr.org/services/nmr/nmrmeetingsummary.html. Another enhancement is the introduction of a new category of papers to Acta Cryst. F, Laboratory Communications. In parallel with the categories of Structural Communications and Crystallization Communications, this new category is for papers that describe special methods, equipment modifications, techniques for accomplishing certain tasks etc. that are related to crystallization or other fields of structural biology. The papers we want to attract contain observations made in the laboratory that are likely to be useful to our readers. Very often, these observations range from tips and tricks to novel procedures or adaptations that are hidden in the methods paragraphs of long papers, or may not be published at all. Our aim is to collect these for Acta Cryst. F and make them accessible to our readers. This issue contains the first example of a paper in the Laboratory Communications category by Tobias Beck and colleagues (Beck et al., 2009) and is titled How to get the magic triangle and the MAD triangle into your protein crystal. It describes the practical aspects of handling the compounds I3C (also known as the magic triangle) and B3C (the MAD triangle) for derivatizing protein crystals and phase determination. As an example, orthorhombic crystals of the serine protease trypsin were derivatized by co-crystallization with B3C. The paper conforms exactly to the spirit of the new category in the sense that it describes a successful experiment in sufficient detail so that it can be reproduced by others and, more importantly, that it can be applied to other problems. We hope that this new category will serve our readers well and we would like to invite you to write up your observations and submit them to Acta Cryst. F.