MetalJet for
X-ray analyticalapplications
SAXS, small molecule and protein crystallography

MetalJet D2+State-of-the-art, high-brilliance X-ray source

Y position [μm]The Excillum MetalJet D2+ features our unique metal-jet anode technology
and advanced electron optics. Achieving significantly higher brightness
and smaller spot sizes than any other available microfocus X-ray source,
the MetalJet can create very brilliant and small beams enabling the closest
possible performance to synchrotron capabilities in the home lab.

0.3

The MetalJet uses a fast flowing liquid jet of

the MetalJet can create very brilliant and

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metal instead of a rotating anode metal target,

small beams enabling the closest possible

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thereby removing the limitations of the rotating

performance to synchrotron capabilities in0

anode, allowing a greater power loading to

the home lab.

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be placed on the metal target without risk of-0.2

destruction. In this way, the MetalJet can-0.4

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-0.2

-0.1

00.1

0.2

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generate a higher brilliance, focused beamof X-rays which can be up to a factor of ~10x

X position [μm]greater than conventional micro-focus rotating

Electron beam spot position over 24 hours

anode X-ray sources.

Line profile through maximum
Horizontal
Vertical

1[a.u.]

0.8
0.6

The MetalJet uses a fast flowing liquid jet ofmetal instead of a rotating anode metal target,
thereby removing the limitations of the rotating anode, allowing a greater power loading
to be placed on the metal target without riskof destruction. In this way, the MetalJet canThe Excillum MetalJet D2+ features our uniquegenerate a higher brilliance, focused beam

metal-jet anode technology and advancedof X-rays which can be up to a factor of ~10xelectron optics. Achieving significantly higher

greater than conventional micro-focus

brightness and smaller spot sizes than any

rotating anode X-ray sources.

other available microfocus X-ray source,

0.4
0.20−500[μm]Line profile through electron
beam spot maximum

50

High stability, low divergencefor better data
The MetalJet generates a high-stability (<0.1The electron beam spot is tightly focused toμm over 24 hours) electron beam spot, which

typically between 5 and 30 μm in size, resulting

translates to a high stability X-ray beam after

in a typical X-ray beam size of 70-100 μm after

the X-ray optic.

the X-ray optic; dependent upon the optic.

The size, shape and take-off agle of theclosely packed, as in protein crystallography,

eletronbeam and thereby the X-ray beam

a low divergence X-ray beam provides betterare software controlled and can be adjusted

data separation, better positional and betterby the user to best fit the sample size andintensity measurements, leading to better

application.

overall data quality. In contrast, a higher

The MetalJet is typically paired with a highquality, low divergence X-ray optic to give thebest data quality. When Bragg reflections are

Lower divergence• Better separation• Better defined reflections• Better intensity integration

divergence X-ray beam leads to broader,poorer defined data, which may overlap,
merging positional and intensity information
leading to inferior overall data quality.

Compact, low maintenance,
lower cost of ownership

Higher divergence

The MetalJet is extremely compact and isThe MetalJet never requires costly anodeavail­able as a stand-alone X-ray source orre-polishing or anode replacements, has noupgrade direct from Excillum, or as part ofmoving parts or ferro-magnetic seals. Evena state-of-the-art X-ray diffraction or SAXS

the filament has been eliminated by design

system from one of our equipment manu­

and replaced with a long life LaB6 crystal

facturer partners.

cathode. Together these improvements• Broader reflections• Poorer separation• Poorer defined reflections• Poorer intensity integrationprovide for more up-time, lower maintenance,
a lower cost and a greater ease of ownership.

Combining the higher brilliance of theMetalJet and either gallium or indium
radiation can provide improved data
quality compared to other traditional
metal targets due to:• Lower air / liquid scatter• Lower absorption and reduced
potential radiation damage
compared with copper radiation.
• Higher accessible resolution• Higher data collection speed andefficiency

Two wavelength options
for up to 0.26 Å resolution
Available with either a gallium (λ =1.34 Å) or anaccessible data up to 0.67 Å resolution forindium (λ = 0.51 Å) rich alloy based target, thegallium and up to 0.26 Å resolution for indium.

MetalJet at 90 degrees in theta, can provide

Small molecule crystallography
Small molecule crystallography uses X-ray

desirable. Use of the MetalJet typically means

diffraction in the determination and study ofshorter experiment times, faster structures

the three dimensional structure of a material

and higher throughput of samples. Small andat the atomic and molecular scale. A single

weakly diffracting crystals, diffract more

crystal of the sample is required and thestrongly, thus providing higher quality data,

resulting X-ray structures provide a to scale 3D

whilst sensitive crystals can be measured

visual map of the atom types, their relative

faster with the MetalJet and suffer lessarrangement and how they are connected indegra­dation accordingly. Twinned crystal data

space. The crystal samples studied arecan be more strongly defined using a MetalJet,

typically, inorganic, organic or organo-metallic

making it more easily identified and potentiallycompounds, primarily from research in thehandled. Very weak diffraction effects,disciplines of Chemistry, Geology and Physics.

inherent to incommensurates, diffuse

As small molecule X-ray crystallography
becomes more automated and routine, there
is increasing interest in the study of moredifficult and specialist materials in which ascattering samples, quasi-crystals and highpressure samples become stronger and may
be more readily measured and investigatedusing the high brilliance X-rays of a MetalJet.

high brilliance MetalJet X-ray source isExample small molecule applications
Small crystals
Tin (IV) compounds are interesting as potential

a 50 μm crystal of [Sn(C2O4)Cl3(H2O)].(C4H7N2)

catalysts and pharmaceuticals due to theirusing a MetalJet X-ray source.

biological activity. As part of a drive to understand these compounds, researchers at the• Crystal size: 0.05 x 0.04 x 0.04 mm3

Universities of Montreal, Cheikh Anta Diop and• R1 = 6.2%

Bourgogne determined the crystal structure ofActa Cryst. 2015. E71, 520–522, M. B. Diop, L. Diop,L. Plasseraud, T. Maris

Absolute structures
Application scientists at Bruker AXS used a• Flack x = 0.024(39) (Parsons‘)

MetalJet integrated into a Bruker D8• Crystal size: 0.15 x 0.05 x 0.04 mm3

VENTURE diffractometer to successfully• Experiment time: 4 hours

determine the absolute configuration of• Resolution: 0.75 Å(2S)-(−)-2,2’-Oxybis(octahydro-7,8,8-trimet-• Completeness: 96%

hyl-4,7-methanobenzofuran), a light atom
structure, where the heaviest atoms are threeoxygen atoms.

• Redundancy: 4• R1 = 3.18%

Heavy absorbers
A group of researchers from the University

which have potential application in the area ofof Montreal recently determined the crystal

luminescent sensors.

structure of the heavily absorbing compound[Au(PPh3) (S2CNMe2)] using a MetalJet source
integrated into a Bruker D8 VENTURE. The
compound was part of a study of materials
based on d10 configured gold (I) compounds• Crystal size: 0.08 x 0.04 x 0.04 mm3• R1 = 3.94%• Absorption coefficient μ (Ga Kα ) = 10.57 mm-1
MolBank 2017, 2017(2), M937, N. Bélanger-Desmarais,
C. ReberExtended metal network structures
Researchers at the University of Basel have

• a = 35.9593(6) Åused a MetalJet mounted on a STOE diffracto-• b = 35.9593(6) Åmeter to study the crystal structures of a series• c = 25.1227(3) Åof extended three dimensional metal network• R1= 8.98%

structures including [Zn2Br4(L)]n. This structure
exhibited long unit cell edges and a large unit
cell volume of 28133.2(9) Å3.

CrystEngComm, 2017, 19, 2894-2902, Y. M. Klein,
A. Prescimone, M. Neuburger, E. C. Constable,
C. E. HousecroftProtein crystallography
Protein crystals are extremely sensitive andHigh brilliance X-ray sources, such as thepoorly defined, due to the large proportion

MetalJet have made a greater number ofof water within their structures. As a result,protein structures and experiments possible

protein structures are ‘floppy’ and the X-ray

in the home laboratory, thereby accelerating

diffraction data is typically of a much lower

research with ease of access and convenience.

resolution quality compared to a small molecule structure. At the same time, the numberof atoms present in a protein structure is very
high and the data (Bragg reflections) to becollected is very closely packed together.

Using the high brilliance MetalJet X-ray source
makes weak diffraction data stronger, reducing
experiment times and potentially reducing
sample degradation. The narrow, focused
X-ray beam is ideally suited to measure even‘‘The X-ray source helps
a lot, in some cases its
use replaces the need forsynchrotron. Our main
goal with purchasing
and using the MetalJet isfocused on studying
smaller crystals. Working
with 30 micron crystals
is no longer an obstacle”.

Protein crystallographers rely on the strongest

the smallest protein crystals, providing com-X-ray sources to combat the issues of air

pact and well-defined reflections. The highersensitivity, small crystals, low diffraction andintensity MetalJet X-rays typically extend thedensely packed reflections. Traditionally, aangular resolution limit of the visible protein

Institute of Biotechnology,

high brilliance synchrotron has been used todata collected and provide more precise

Czech Academy of Sciences,measure full protein data leading to protein

reflection positions and intensities, leading tostructure determination, whilst home labora-

higher resolution protein structures.

tory instruments have been used for protein
screening to identify the preferred crystals formeasurement at the synchrotron.

Example protein applications
Fast data collection forhigh throughput screening
As an example of a fast data collection,• Exposure: 1 second

applications scientists at Bruker AXS recorded• Crystal size: 0.1 x 0.08 x 0.05 mm3data on a crystal of a cyclin-dependent kinase• Completeness: 97.5%(CDK) using a MetalJet X-ray source mounted• Multiplicity: 3.68

on a Bruker D8 VENTURE system. The complete• Rmerge : 6.58%

experiment lasted 200 seconds and consistedof 100° of data with the resulting 1.95 Å data
allowing for a structure solution by molecularreplacement.

• Rpim : 3.58%

Dr. Jan Dohnalek,

BIOCEVMembrane proteins in-house
The successful data collection and structure

Data were collected in a total experiment

solution of membrane proteins is notoriously

time of ~2.5 hours to 2.77 Å resolution and thedifficult and is rarely achieved. Even rarer isstructure was successfully solved by molecular

the successful determination of a membranereplacement.

protein structure using an in-house X-ray
diffractometer system, rather than a high• Scan width: 0.1°

brilliance synchrotron radiation source.

• Exposure time: 6 seconds

A small crystal of GPCR (Human Orexin• Multiplicity: 3.2

receptor Ox1R-StaR®) has been successfullymeasured at Bruker AXS using an in-house
MetalJet X-ray source mounted on a
D8 VENTURE diffractometer.

• Crystal size: 0.08 x 0.08 x 0.05 mm3• I/sigma: 8.0• Rpim : 7.62%• Rwork / RFree : 0.244 / 0.2721

Ligand-enzyme
co-crystallisation studies
Researchers at the University of Wisconsin• Resolution: 2.15 Å(Department of Biochemistry) and the• Completeness: 99.3%

National Research Council Canada,• Rmerge: 7.1%

Human Health Therapeutics, recently• Multiplicity: 7.1

solved the structure of WlaRA(TDP-fucose-­3,4-keto­isomerase) from
Campylobacter jejuni using data collectedwith a gallium MetalJet D2+ X-ray source.

Glycobiology. 2017, 27(4), 358-369, Z. Z. Li, A. S. Riegert,
M. F. Goneau, A. M. Cunningham, E. Vinogradov, J. Li, I.
C. Schoenhofen, J. B. Thoden, H. M. Holden, M. Gilbert

SAD phasing in-house
Application scientists at Bruker AXS have

Using one 70 μm crystal, a complete data

determined the crystal structure of Thaumatin

set was collected to 1.65 Å in <3 hours. The

obtained from Thaumatococcus danielii byexperimental phases were derived from thesulphur-SAD phasing methods using data

anomalous signal of the sulphur atoms andcollected in-house on a D8 VENTURE diffraction

these allowed 95% of the protein backbone

system with a MetalJet X-ray source.

to be traced.

In-situ X-ray Crystallography
In-situ crystallography is a technique in which

Multi-well crystallisation plates are typicallyprotein crystals undergo X-ray diffractionof plastic construction and exhibit low X-ray

screening and or data collection whilst in atransparency, high X-ray absorption andmulti-well crystallisation plate and theirsignificant X-ray background scatter, all oforiginal growth media/conditions.

which serve to reduce and/or obscure theTypically, X-rays are directed from one side of

X-ray diffraction signal to be studied.

the multi-well plate, pass through the plate

The MetalJet is the ideal choice of X-ray source

and crystal and out the opposite side of thefor in-situ X-ray diffraction in the home labora-plate, where the diffraction data are collected

tory due to the following unique combination

on an X-ray sensitive detector.

of technical features:

In-situ X-ray diffraction offers the following• The potential to tune the X-ray beam size
through the software, means the X-ray beam

benefits:

may be matched to the size of the crystal• Automated, rapid screening and identifica-and precisely focused on to the crystal oftion of large numbers of potential protein

interest, rather than a group of crystals.

crystals without risk of damage to theThis also means that a much smaller area ofcrystals

plastic plate is illuminated by the X-ray beam

• The identification of protein crystals fromleading to reduced background scatter.

non-crystalline objects, salt crystals and• The higher X-ray brilliance of the MetalJet
combined with the lower X-ray absorption

other impurity crystalsof gallium radiation; when compared with• The identification of the best protein

copper X-ray sources, means that the X-ray

crystals for further X-ray study

signal obtained from in-situ diffraction isgreater for the MetalJet.

Small Angle X-ray Scattering (SAXS)
Small Angle X-ray Scattering is used to study

the bulk material. The scattered signal is

the structure of materials in the 1 nm to ~200

typically recorded at diffraction angles of <6°

nm range. The materials typically studied

and the sample is positioned at a long distanceinclude polymers, metals, colloids, liquidfrom the detector. The measured scattered

crystals and biological samples e.g. proteins.

signals are accordingly extremely weak.

The information determined relates to theFor this reason, SAXS measurements benefit

particle size, shape, distribution and orienta-

from the use of a high brilliance X-ray sourcetion, porosity, surface features and internalsuch as the MetalJet, which makes weakstructure. A SAXS sample requires very little

scattering effects, stronger, more visible andpreparation and results are representative of

more readily studied.

Example SAXS applications
FibresApplication scientists at Bruker AXS have useda NANOSTAR instrument equipped with aMetalJet (200W at 70kV) to record a series ofSAXS scattering plots of a very thin fibre froma rat tail tendon. Providing intensity gains ofmore than 50x compared to state-of-the-art
sealed microfocus tubes.

Images courtesy of Bruker AXS.

Biological (BioSAXS)
Researchers at Nanyang Technical University,
A*STAR, University of Louisville, Rosalind Franklin
University of Medicine and Science and Kyung Hee
University have used a MetalJet equipped SAXS
instrument to study the Bcl-xL protein, a key
regulator in mitochondrial calcium ion transport.
The protein was treated with a mild detergent andstudied during the formation of a dimer resulting
from three-dimensional domain swapping (3DDS)of helices α6-α8 between two monomers.
Sci. Rep. 5, 10609 (2015), S. Rajan, M. Choi, Q. T. Nguyen,
H. Ye, W. Liu, H. T. Toh, C. B. Kang, N. Kamariah, C. Li,H. Huang, C. White, K. Baek, G. Grüber, H. S. Yoon.

Metals and colloids
Researchers at the Slovak Academy of Scienceand STU Centre for Nano-diagnostics performedin-situ tests on a strain gauge, based on a monolayerof colloidal gold nanoparticles deposited on aflexible Mylar foil. The tests were monitored bySAXS where the high brightness of the MetalJet
allowed a very fast data collection, with 10 seconds
temporal resolution.
Sensors and Actuators A: Physical, 2016, 241, 87-95, K. Vegso,
M. Jergel, P. Siffalovic, M. Kotlar, Y. Halahovetsa, M. Hodasa,
M. Pellettaa, E. Majkovaa

Polymers
The investigation of polymers is one of the main areasof focus of the Soft Matter Analytical Laboratory(SMALL) at the University of Sheffield. Followinga £2 million infrastructure investment in 2016 andthe purchase of a new SAXS system with a gallium
MetalJet X-ray source, their first new resulting
publication was a co-polymerisation study ofStyrene with N-Phenylmaleimide.
Macromolecules, 2016, 49 (18), 6731–6742, P. Yang,
O. O. Mykhaylyk, E. R. Jones, S. P. Armes.

All registered and unregistered trademarks, domain names and copyrights herein are the property of their respective owners. Excillum, MetalJet, MetalJet D1, MetalJet D2,MetalJet D2+, MetalJet C2, MetalJet E1, MetalJet E1+, NanoTube, NanoTube N1, NanoTube N2, and NanoTube N3 are registered trademarks or trademarks of Excillum AB.
Excillum’s X-ray sources and technology are protected by several patents including, but not limited to, US Patents Nos. US 6 711 233, US 8 170 179, US 8 681 943, US 8 837 679,
US 9 171 693, US 9 245 707, US 9 380 690, US 9 530 607, US 9 564 283, US 9 947 502, US 10 784 069,
US 10 818 468, US 10 825 642, and Chinese Patents Nos. ZL 01816396.3, ZL 200780026317.0, ZL 200980155094.7, ZL 200980158566.4, ZL 201080070417.5, ZL 201280075230.3,
ZL 201410213235.9, ZL 201510020687.X, ZL 201610033696.7, ZL 201780012946.1, and other corresponding national patents and patent applications pending.

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