powdery mildew infection on leaf surface in the cryo-SEM

Frequently Asked Questions

The Microscopy group often answer questions from fellow scientists, teachers & students, and even people doing art projects, regarding this exciting and evolving area of science. Below are a number of the most frequently asked questions along with the answers.

Q. Can I visit the JIC with my school to see the microscopes?
A. In the past, we agreed to a few demonstrations for school groups each year. However, the number of requests is becoming unmanageable so we have had to draw a halt to this. We hope that this website will answer many of your questions without the requirement for a demonstration. However, we are considering launching an annual open day where teachers can apply in advance to bring their classes to see the electron microscopes, but this will be restricted to students doing A-levels sciences only.  It is difficult to accommodate large numbers of people in the microscopy facility, mainly because the rooms are designed for use by only one or two people at a time and so there is simply not enough space.  For further information, please contact the JIC Communications Team (jic.communications@bbsrc.ac.uk).

Q. What kinds of electron microscopy techniques are available at JIC?
A. The short answer is: TEM and SEM.  For a more detailed guide to the exact techniques available, take a look at the 'Facilities' section of this website.

Q. How long does it take to prepare typical samples for viewing in the electron microscope?
A. For the TEM, upon receiving a live sample, a typical turn-around time is ~1-2 weeks for fixation, embedding, sectioning and contrast staining grids before they can be imaged. If immuno-labelling is required, it will be at least two weeks.  For SEM, sample preparation time is generally much shorter, sometimes only a matter of a few minutes, especially if the samples are cryo-fixed.

Q. Why does the sample size have to be so small?
A. For the TEM, samples must ideally be less than 1 mm3 to begin with for good preservation of morphology during the fixation stage. The main limitation is the speed and extent of penetration of fixatives (typically glutaraldehyde). If the fixative doesn't penetrate throughout the tissue, then it will be poorly preserved. So if, for example, we want to look at a leaf, the leaf will have to initially be cut into lots of tiny pieces, each around <1 mm3, at the time of fixation.  Then, in general, we will only section one or two small pieces to get an idea of what the sample is like. Remember, if you’re going to have to cut slices of the sample that are only ~100 nm thick for imaging, then 1 mm provides ~10,000 slices — way too many to search for a rare feature. To "preview" or find interesting sections of the sample, we typically perform light microscopy of stained "semi-thin" sections (typically 0.5 µm) first. We would then focus our efforts in thinner slices.

Q. I am a local teacher.  Can I have some electron micrographs for use as teaching material in the classroom?
A. We advise you to look at the other websites we recommend, where you can find a wealth of teaching material and images. If you don't find what you're looking for, you could contact the JIC Communications Team (jic.communications@bbsrc.ac.uk) and/or the TSN (Teacher Scientist Network) with further details of your request.  We may be able to help.

Q. Is it possible to buy some of the images taken on the JIC microscopes?
A. We have a set of six postcards.  They are black and white, scanning electron micrographs, taken by Kim Findlay (our senior electron microscopist), on the JIC’s electron microscopes.  Please contact the JIC Communications Team (jic.communications@bbsrc.ac.uk) for further information.

Q. Would it be possible to come and use an electron microscope?
A. We do not permit members of the public to use the electron microscopes; sorry!  We are sure you will understand that these are expensive pieces of equipment, requiring extensive training to be able to use them and access is required at all times for the research staff and students working at the JIC.

Q. I'm doing an art project based on images of food decay/cells etc and would like to visit the microscopy department for inspiration.  Is that possible?
A. Please contact the JIC Communications Team (jic.communications@bbsrc.ac.uk), telling us specifically (if you can) what you want to see.  We may be able to make arrangements for you to have access to some images but cannot guarantee a visit to the microscopy department per se.

Q. I would like to get some images taken of my own samples on your microscopes.  Is it possible and how much would it cost?
A. We do occasionally accept projects from external requestors, but these are confined to legitimate scientific collaborators and, very occasionally, sometimes an industrial company, but never from members of the public.  However, we have to charge at full economic cost, which is very expensive. If you have a legitimate request and want a quote for your project, please contact the Microscopy department directly (kim.findlay@bbsrc.ac.uk).


The mystery image on the "About Microscopy" page is of the upper surface of the petal of a common daisy flower from the lawn at JIC. It was imaged on the Zeiss SEM.