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 two 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.

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.

Currently, Tier 3 access to support hit follow-up chemistry is under discussion.

Applying for Standard Access: 

• Complete the Standard Access Form which can be downloaded here.  The form includes complete instructions for submitting via the User Administration System (UAS). An example of a completed Standard Access Form can be downloaded here for your guidance
• 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's 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' 
• 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.'