Suzannah Povey-White, Author at Quorum Technologies Ltd


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.

 


T1_cpd_6nmPt1_0038_LMULX4s-1-1280x936.jpg

Plants are full of surprises, they are not only host for microorganisms but also for very small insects;

ImageJ=1.53f
unit=u00B5m

here we see a spider leg protruding from a cross-section of a banana leaf.

Specimen: Musa sikkimensis ( banana) leaf,  preparation and imaging from Anna Walkiewicz
Image: leaf cross-section with an unexpected inhabitant
Sample preparation: protocol for plant tissue preparation followed by Critical Point Drying (K850 CPD) and coating with 8nm of Pt (Q150V S plus).


Springtail-skin-1280x883.jpg

Springtails are extraordinary creatures, they are arthropods living in soil, plants and decaying material adapted to the environment by developing a special comb-like pattern on their skin. This rhombic-hexagonal structure is responsible for the non-wetting properties of the springtail body.

Sample: springtail colony from orchid bark. Sample preparation and imaging from Anna Walkieicz: bio preparation protocol followed by Critical Point Drying (K850 CPD) and coating with 8nm of Pt (Q150V S plus).


Picture1-1280x888.jpg

Pollen are small bioaerosol grains consisting of a single cell containing two male gametes essential for sexual reproduction of flowering plants. Typically, these bioaerosols range from 10 to 200 μm, are aerodynamic and low in density. These characteristics are essential for wind-pollination (anemophily) and/or insect-pollination (entomophily) – the transport of pollen from male stamen to the female stigma.

The grain wall is comprised of a tough chemically stable substance known as sporopollenin, which is highly resistant to environmental damage. It is punctuated with small openings called apertures which allows the male gametes to escape during pollination.

Pollen is typically classified by its distinctive structural features, i.e., variation in size, shape, number of apertures and surface texture, which also makes it possible to identify and classify a plant at family and genus level, and often even species level.

Anemophilous (inconspicuous or non-flowering) plants typically produce enormous quantities of very lightweight pollen grains, usually with air-sacs. Whereas entomophilous (insect-loving) plants produce pollen that is relatively heavy, prickly, and sticky to cling to the insects attracted by the flowers’ nectar and showy colours.

SEM micrographs of pollen grains below are from a Papaver Nudicaule (Iceland Poppy) and a Geranium (Wild Purple Cranesbill) plant image imaged using a FE-SEM prepared using the Quorum PP3010 cryo-preparation stage by Dr Mark S. Taylor.


Picture2-1280x889.jpg

Calcium oxalate is frequently found in plants, leafy vegetable such as spinach, almonds and dates in the form of tiny needle like raphides. Whilst these play a central role in controlling calcium regulation, herbivory and metal detoxification, unfortunately if consumed, calcium oxalate can lead to kidney stones. Out of all the 3 forms of calcium oxalate, the monohydrate form is the one widely reported to cause kidney problems.

Images show needle like raphides of calcium oxalate crystals observed at Quorum Technologies using an Ultra high-resolution Field Emission Scanning Electron Microscope (FE-SEM), equipped with a PP3010 automated, column-mounted, gas-cooled cryo-preparation/ transfer stage chamber www.quorumtech.com

Small cross-sections of the plants were cut and mounted on a universal cryo-stub using mounting media – a 50:50 mixture of Tissue-Tek OCT (Optimal Cutting Temperature) compound (Agar Scientific) and colloidal graphite (G303 Sakura) to fix and aid electrical conductivity.

The Tissue-Tek OCT (Optimal Cutting Temperature) being a mixture of clear water-soluble polyethylene glycol with polyvinyl alcohol and the colloidal graphite a mixture of graphite, propan‑2‑ol, butanol and 1-methoxy-2-propanol. The cryo-stub with sample was then mounted onto a specimen shuttle plunge frozen (vitrified) in slushed nitrogen (LN2) and transferred under vacuum conditions to the cryo-preparation chamber.

On the preparation cold stage, maintained at -140°C (anti-contaminator -175°C), the vitrified samples were cleaved with a cold knife, sublimated at -90°C for 2 – 3 min and then coated in situ with Iridium using a current of 5 mA for 60 – 90 s to ensure electrical conduction. Cryo-SEM imaging at -140°C (anti-contaminator -175°C) was carried out at acceleration voltages 1-1.5 kV and emission currents 15 – 20 µA at working distances 8 – 12 mm detecting secondary emitted electrons.
(Imaged by Dr Mark Taylor of Quorum Technologies, UK) #microscopy #Cryoprep #quorumtech #samplepreparation


cpd_water-daphnias_algies6nmPt_0023_SEUL-2-2XX.jpg

Quorum Technologies would like to celebrate International #womeninscienceday,
Dr Anna E. Walkiewicz is the Applications Specialist at Quorum Technologies. She holds a PhD from the University of Birmingham, where she researched the recognition of chirality at the nanoscale.

ImageJ=1.53f
unit=u00B5m

This is shelled ameboid from fresh water sample.
Sample preparation: Biological sample prep protocol followed by critical point drying in Quorum K850 and coated with 6nm of Pt in Quorum Tech Q150V S Plus. quorumtech.com


Diatoms-combined2Small-1280x896.jpg

Imaging Spotlight. 

Diatom algae:
One of the most sophisticated frustule structures.
Sample preparation:
Biological tissue processing followed by critical point drying using Quorum Technologies K850 CPD and 8nm Pt coating in Q150VS Plus. Imaged by Dr Anna Walkiewicz, Applications Specialist
Daphnias algies


UNITED KINGDOM

Headquarters

Judges House, Lewes Road,
Laughton, East Sussex.
BN8 6BN

+44 1323 810981

www.quorumtech.com

[email protected]

UNITED KINGDOM

Working Hours

8.30 – 5.00 pm Mon – Thu
8.30 – 4.00 pm Fri
QUICK LOOK

Latest News


No more posts


GET IN TOUCH

Follow Our Socials

Keeping in contact with our customers via social platforms as well as traditional telephone and email.