Standard Access

In the standard access, each proposal covers a single target. Proposals are evaluated by an independent Peer Review Panel (PRP) for access via one of three tiers:

Tier 1 Access:

• For experiments where a credible strategy is not yet in place for following up any hits, yet feasibility of the screen itself is high, or the science justifies exploratory XChem access to establish feasibility.  
• While such proposals might have been unsuccessful previously; we are now welcoming them for initial feasibility assessment and (if required) discussions with the XChem team on formulating a credible hit follow-up strategy.  Successful Tier 1 projects can be fast-tracked for Tier 2 access through rapid online peer-review.

Tier 2 Access:

• For experiments where feasibility is demonstrated and a robust strategy is articulated for progressing XChem hits to potency.  These correspond to proposals that were successful in the previous, un-tiered access mode.

Tier 3 Access: Hit-to-lead development.

• For follow-up work to a successful XChem screen, where large numbers of compounds (>50) need to be tested in crystals.  Applications require:  a science case; a clear rationale for compound design; confirmation that orthogonal assays are in place and evidence of sensitivity; and an experienced experimenter to be named. 
• Projects can be fast-tracked for Tier 3 access through rapid online peer-review.

Approved proposals are allocated a certain amount of beamtime, the use of which needs to be appropriately allocated to users.  The PRP may decide to re-assign the tier that Diamond finally offers.

Applying for Standard Access: 

• Complete the Science Case Form, and submit the filled form via the User Administration System (UAS). 
• On the UAS:
  • Select the 'Proposals' tab at the top of the screen
  • Press: 'Create New Proposal'
  • Select: 'No - This is a completely new proposal' in the Beamtime Request Wizard
  • Select: 'Standard - A one-off proposal for a six month allocation period.

XChem users can access different European partnerships to help for access or hit-to-lead chemistry (iNEXT-DIscovery, EUbOPEN and EU-OPENSCREEN). More information on those partnerships and how to access them can be found here.

Some instructions for specific fields are provided here: 

Science overview tab:

• Title:  ~10 words, and include target name and (if relevant) disease or biological relevance
• Abstract: 2-3 sentences, ~50
  • should be understandable by a reviewer who is not a specialist in your area of biology.
  • must allow reviewers to recognise potential conflict-of-interest without seeing the full proposal.
• Science Case: Download and fill in the XChem science case template (it's the same one that's linked earlier on this page). Detailed instructions are at the end of the document.

Beamlines tab:

• Beamlines: select 'XChem'
• Number of Shifts:
  • For Tier 1 enter '1'
  • For Tier 2 enter '4' (or '3' if you have previously completed a Tier 1 screen on this target)
  • For Tier 3 enter '1' for every 200 compounds
• Access to RCaH: select 'Yes'

Experimental methods tab

• Select 'Create New Experimental Method'
• Enter new experiment method details e.g. copy-paste the following text to the corresponding fields (the risk assessment and COSSH are available on request):
  • Name: 'fragment screening in lab XChem and I04-1'
  • Sample method statement: 'Crystals will be brought pre-grown by users or grown using Diamond and RCaH crystallization robotics. Fragment compounds will be transferred to crystal drops using the ECHO liquid handler.  Crystals will be harvested using a Shifter device and frozen in liquid nitrogen.  See lab standard 7 (LSRA7) here'
  • Beamline method statement: 'Crystals frozen in lab XChem will be transferred to beamline I04-1 and auto-collected in cryogenic queue mode, with or without the users present.  Crystal loading and unloading will be performed by local contacts or occasionally users themselves.'