FAQs - Macromolecular Crystallography

That depends on how well they diffract! If you are collecting on MX2 (the microfocus beamline), a “normal” protein crystal sample would usually need to be larger than 3-5 microns in its thinnest dimension. Small molecule crystals can be sub-micron if they diffract well. Larger crystals (greater than 50-100 micron) are more suitable for MX1.

18mm pins with a standard base. Pins with copper jackets are recommended, as they are easier to load into cassettes. SPINE-style and ALS (Advanced Light Source) pins are not supported if you are using SSRL cassettes as they will cause the robot to jam.

SPINE pins are accepted, however, if you using AS (Australian Synchrotron) type pucks.

From Crystal Positioning Systems: (http://www.crystalpositioningsystems.com/).

A complete loading and shipping toolkit (strongly recommended for new robot users) is catalogue number CP-111-020 (this includes one cassette). Additional cassettes (without pins) are catalogue number CP-111-011. When ordering cassettes users can specify a cassette ID such as mylab01, mylab02, etc., that will be engraved onto the top of the cassette and this helps users and staff to easily identify cassettes.

Please contact the MX team by using the following address:

MXPrincipal@ansto.gov.au

Most of our users use the Taylor-Wharton CX100 dewar and hard shipping case (catalogue number CX10-8C00).

Information about shipping samples to the Australian Synchrotron (domestically or internationally) can be found here.

If you have provided a valid email address in the sample shipping form you will receive automated email notification when the dewar arrives at the beamlines, when the dewar is topped up with liquid nitrogen and when the dewar is moved from the beamlines for return by your nominated courier company. If you think your dewar should have arrived and have not heard, please contact beamline staff.

We recommend Pakair for sample shipping. ANSTO only reimburses the costs of shipping when using this company.

If you are not asking for reimbursement, you are free to use a company of your choice, but please check whether they will service the facility. Email as-mx@ansto.gov.au for more information.

Before you can use the beamlines remotely, you will need to complete the remote user induction on the Portal. Check under 'My Exams' on the Portal to find any training you haven't yet completed. 

Browse to https://aswebmx.synchrotron.org.au/menu/ and look for Remote Access for MX1 or MX2

All AS users have been provided with the Popup authentication username and password. 

Browse to https://aswebmx.synchrotron.org.au/menu/ and look for Remote Access for MX1 or MX2

All AS users have been provided with the Popup authentication username and password. 

You will be provided with the experiment access password via email at the start of your beamtime.

If you have decent broadband (ADSL etc) you can double click on the “Areavision” icon and it will open the large display. Wait until the window opens and then click “start video”. As this window is sized for a large monitor you may have to double click on the top bar of the window to resize it to your monitor.

If there are interruptions to your network connection remote sessions may drop out. If this does happen, re-connect to the beamline using the links in https://aswebmx.synchrotron.org.au/menu/. If you have repeated dropouts please try closing all other applications that may be using bandwidth (email, webpages etc) and retry. If this does not work, call beamline staff or the control room.

Check on the Portal to see which beamline scientist will be your support for your experiment. During office hours, you can call your support scientist. Their phone numbers will be included in your 'Beamline is ready for experiment' email, and are also pinned to the walls in the MX user cabins. 

After hours, please contact the control room on 03 8450 4123 or +61 434 600 225.

The focused full beam is 20x15 microns. The micro-collimator allows users to insert 20, 10, and 7.5 micron platinum apertures into the beam. This produces a beam about the same size as the aperture in the vertical and 1.5 times in the horizontal e.g. the 10 micron aperture produces a 10x15 micron beam.

You can! Both MX1 and MX2 are equipped for MAD scans. There is a link to the MAD scanning GUI through the PyPanel on the beamline computers. You can run excitation scans to confirm the presence of selenium (or other scatterers) and MAD scans through this GUI. 

MX1 has user-changeable energy from 8.5 to 17.5 keV.

MX2 has user-changeable energy from 8.5 to 15.5 keV.

Beamline staff can assist (during on-site hours) users to access energies below and above this range.

This depends on several factors: what the anomalous scatterer is, how strong the signal is, and how radiation-sensitive your crystals are. For most Se-Met crystals a two-wavelength MAD experiment with the high energy remote (from 5-500 eV above the peak) collected first and followed by the inflection point is highly successful. Be careful to collect enough data at each wavelength to have an anomalous multiplicity of at least 4 (>7 is preferable). Remember that radiation damage within a data set will destroy your signal so it is better to attenuate heavily and collect redundant MAD data. For example, it is worth sacrificing 0.2 Å in resolution (by attenuating more) to reduce radiation damage for your MAD datasets. Most users collect a high-res native as well.  

MX provides automatic processing with XDS so you can assess data quality during your beamtime. There are also options to merge datasets or retrigger processing jobs through our GUI. 

The CIFs generated through MX autoprocessing will autofill the required fields for you. If you reprocess your data, please ensure you've copied across the CIF fields that were present in your auto processed data. In particular, please retain information about the location of data collection! Having this information in the CIFs makes it possible for MX staff to keep track of how many structures are being solved using the beamlines.