Suzannah Povey-White, Author at Quorum Technologies Ltd


In this series Dr Anna Walkiewicz, the Quorum Application Specialist, will talk about different processes within the sample preparation workflow and breaking them down into simple steps, solving common problems and looking at how to improve efficiency and efficacy.

Coating for SEM. How to choose vacuum level, metal and thickness.

In this Coffee Talk Dr Anna Walkiewicz will guide you through metal coating for SEM imaging. During the tutorial, you will learn what metal to choose for different applications and how coating process parameters influence coating quality.

Register here


In this series Dr Anna Walkiewicz, the Quorum Application Specialist, will talk about different processes within the sample preparation workflow and breaking them down into simple steps, solving common problems and looking at how to improve efficiency and efficacy.

The first coffee talk, The Scary Vacuum, will be addressing issues regarding the vacuum: why do we need to consider if our samples are sensitive to the change of pressure and how they will behave in the vacuum environment.  Dr Anna Walkiewicz will be giving advice how to prepare samples in the correct way, so we see their natural appearance rather than an outcome of the pressure change modifying their morphology. Register here Coffee Talks with Dr Anna Walkiewicz – The Scary Vacuum 14th September – Quorum Technologies Ltd



See a piece below from our customers at the Cambridge Advanced Imaging Centre at Cambridge University.

Cambridge Advanced Imaging Centre (CAIC) forms the hub of a network that draws together imaging activity across the whole University to serve the biomedical community. Many powerful modern imaging techniques have recently been developed, yet their exploitation in biology and biomedical research has largely been prevented by the high cost of their translation into widely available instruments and the specialist skills required for their use, including handling the vast volumes of data they generate. As a consequence, instruments developed in laboratories within specific Cambridge research programmes are often not available to the University’s wider biomedical research community.

Our Verios 460 SEM is equipped with a Quorum PP3010T cryo-SEM preparation system. Cryo-SEM allows imaging of soft, hydrated biological or materials samples in a frozen state. One of the major advantages of cryo-SEM is that samples can be imaged with minimal preparation without the need of any prior fixation or dehydration steps; a disadvantage is that sample throughput is fairly low compared to other methods. Specimens are mounted on an appropriate cryo-SEM shuttle, are plunge-frozen in slushed liquid nitrogen and then transferred to a cooled prep stage. Once on the prep stage, samples can be fractured, sublimed to remove any residual ice, and coated to improve contrast and conductivity (CAIC routinely uses a platinum target). Then, the sample is transferred onto the SEM cryo-stage for imaging. As cryo-SEM requires about 2h of run-up and run-down time of the system apart from the actual imaging time, we recommend half-day or whole-day bookings.

Some images below from their cryo-SEM



Stuart discusses his role in the School of Chemical and Process Engineering ‘Our goal as a unit is to perform world leading research. This is only possible by having cutting edge equipment supported by experts in the field.’

Stuart says ‘As we are a user facility that services the whole university and external universities, our current work varies significantly from day to day. We are currently working on cryo serial sectioning on self-assembling peptide & chondroitin sulphate hydrogels which aid cartilage growth in knee joints, which is a collaboration between biological engineering and mechanical engineering here at Leeds.

Quorum first installed a PP3010 at Leeds Uni in April 2017, and we have successfully partnered with them across multiple projects.  Stuart says of the Quorum equipment ‘Our Quorum PP3010 is currently the only cryo-SEM equipment in the university, so it is a key part of the research performed. It is reliable, easy to use and is stable enough to perform not only high-resolution imaging but also FIB cutting. We have specifically requested the Quorum P3010 to be installed on our new system with will be delivered at the end of the year. We also have a Quorum carbon coater which is extensively used for high-resolution coating of SEM and TEM samples.

We asked Stuart what the main benefits of the PP3010 cryo-prep system, ‘The main advantage of the quorum system is flexibility. It’s very convenient to be able to fracture, sublime and coat in the same system, and to be able to sublime before quickly checking if the features of interest are revealed then continue to sublime if not. The resolution of the SEM doesn’t seem to be affected by the cryo system, as it is quite important to obtain good quality, high resolution images.

We wanted to share some of these images with you from this exciting project, and we look forward to helping many more customers with these systems in the future (images supplied by Leeds University).

We have linked a couple of the projects relating to the images below.

Lead sulfide scaling in multiphase systems and co-precipitation in the presence of calcium carbonate – ScienceDirect


Dr Anna Walkiewicz, the Quorum Technologies Application Specialist, is running a series of informative and educational webinars across this autumn looking at all aspects of sample preparation. The first talk is on 12th September at 11am BST, until 11.30am BST.

In this series, Dr Walkiewicz will be tackling different processes within the sample preparation process and breaking it down into simple steps, solving common problems and looking at how to improve efficiency and efficacy.

  • CT 01-The Scary Vacuum – 12th September – How will samples behave in the vacuum?
  • CT 02-Dehydration 26th September – Why is it so important? Why do we dehydrate samples? Do we need anything before dehydration? Means of tissue fixation
  • CT 03- Critical Point Drying 10th October – is it really so complex?
  • CT 04- Mounting samples 24th October – exposing the most relevant parts. Coating – why do we coat samples?
  • CT 05- Coating for SEM 7th Nov – What do we use for coating and when? Vacuum level, metal choice, thickness

To register to watch these events, please visit our events page and fill out the form


Cryo-SEM of microcapsules
Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are extremely important in human physiology. The primary source is typically obtained from fish oils. Whilst there is scientific evidence linking the consumption of ω-3 PUFAs to reduced risk of breast and prostate cancer, high blood pressure and blood circulation – the daily intake in many Western societies falls below the recommended minimum levels. Taking supplements and enrichment of foods is an ideal way to increase the ω-3 PUFAs levels in the diet.

Microencapsulation with modified cellulose by spray-drying provides an alternative way of supplementing where the final product is a fish oil powder additive. The cellulose coating surrounding the oil also improved the stability against oxidative rancidity for up to 12 – 24 months.

The microstructure and encapsulation efficiency can be determined by various methods including cryo-electron microscopy. The cryo-SEM micrograph below shows a variety of spray-dried microcapsules ranging from 1.5 to 17 μm, prepared for imaging using the Quorum PP3010. Preparation includes applying a thin layer on mounting media, vitrification in slushed N2 (-210 °C) and sputtering with Pt (1 – 2 nm). Inset image shows the cellulose coating of a fractured capsule of diameter ≈ 25 μm with wall coating thickness ≈ 571 nm.

Dr M. S. Taylor

Single-cell organisms like algae are one of the most fragile specimens and require very careful and complex preparation before SEM imaging.
Choosing the right method and the support for such a specimen is key to successful imaging.

Here we present an outcome of using Aclar support for freshwater life imaging. The sample was subjected to fixation with 2.5% glutaraldehyde, rinsing with 1% sodium phosphate buffer and dehydration in a series of ethanol concentrations before critical point drying (Quorum K850) and coating with platinum-8nm in Q150V Plus.


Due to unforeseen circumstances we will no longer be able to offer the items SC7620 and the associated carbon fiber attachment with immediate effect. This refers to the product numbers: SC762011oV, SC7620240V, SC7620CF110V and SC7620CF240V.

This issue has arisen suddenly and although we have worked hard exploring other options to prevent this outcome, the cause has been out of our control. We will continue to support previously purchased systems for 7 years in line with standard end of life cycle.

We understand this may cause disruption to you and sincerely apologise for this inconvenience and ask that you will be understanding towards us on this issue.




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