Who can use the Electron Microscopy Core?How can I schedule time on the EM Core's microscopes and other instruments?
Can I learn to use Core equipment and protocols?
Can I see my samples immediately when I bring them in?
How much does it cost to image a sample in the electron microscopes?
How should I submit my samples to the EM Core?
How should I acknowledge the EM Core and instrument grants in my research?
How should I describe the Core's instruments in my research write-ups?
I want to do electron microscopy of cultured cells. How should I prepare my samples for viewing?
Q) Who can use the Electron Microscopy Core?
A) Our primary mission is to serve the research and education needs of the University of Missouri system, and we give priority to UM researchers and students. We also occasionally provide services to clients from other academic institutions, government, and other users outside the UM system. Please contact Core staff with any questions.
Q) How can I schedule time on the EM Core's microscopes and other instruments?
A) We are using on-line calendars to keep track of microscope schedules, staff committments, and scheduled events. Please check the calendars to see when the instruments are open, then call or email Core staff to schedule times. We update the calendars as appointments are made, so if we do our jobs (!) they should always be current. You can link to the calendars below:
Hitachi S4700 FESEM
JEOL 1400 TEM
Specimen Preparation InstrumentsOur other instruments are less heavily scheduled, so normally you can just call or stop by the lab to see if they are available. If the need arises or our clients request it, we will add other equipment to the calendars.
Q) Can I learn to use Core equipment and protocols?
A) Yes. Core staff can train you to operate all equipment and to perform any protocol we are equipped to handle. (See our training and course information links at the left.) In most cases, independent work can substantially reduce the costs involved in completing a research project, and training can be done while working on your own research.
Due to heavy service work loads, Core staff has scheduling priority on all specimen preparation equipment, but all instruments are available for independent use when not being used by staff.
Q) Can I see my samples immediately when I bring them in?
A) Not usually. The EM Core’s goal is to turn samples around within one week of submission, if the current work load permits it. Depending upon the type of specimen, sample preparation for transmission electron microscopy involves several steps, including one to three chemical fixation steps, solvent dehydration, infiltration and embedding with resins, production of ultrathin sections, and staining of the sections. If immunocytochemistry is required, this adds another series of steps. Scanning electron microscopy involves fixation, dehydration by solvents and critical point drying, mounting, and coating with metals or carbon. The process is labor and time intensive and can require several days, or longer if the project load is heavy at the time.
The good news is that some types of samples can be prepared very quickly, such as bacteria, viruses, or other samples suitable for negative staining. Some SEM samples only need to be mounted and coated for viewing, which can be a very rapid process taking less than an hour. Also, use of microwave processing techniques can cut the preparation time necessary for many specimens from days to hours (an extra charge may apply). Consult with Core staff for an estimate of turn-around time for your specific specimen.
Q) How should I submit my samples to the EM Core?
A) Every sample is different. Normally, it is best to fill out a Sample Submission Form, bring biological samples to Core staff, and let us handle the preparation, or advise you on how you may do it yourself. Please note that samples for electron microscopy should not normally be prepared with fixatives used for light microscopy, such as formalin. Staff will be happy to provide protocols (free!), advice (free!), and fixatives (not free), if you would like to collect your own samples. Non-biological samples often (but not always!) require minimal preparation and can be brought in as they are. The safest approach is to call or email Core staff before beginning your project. We will be happy to provide consultation at no charge. It is very useful if the researcher can provide references or reprints relating to EM projects similar to the one being proposed, since this can save time and materials (=money) in reinventing the wheel.
Please note that it is very important that all samples be completely and accurately labeled with the researcher's name and the contents of sample containers. This is especially important when particularly hazardous materials are involved, such as strong acids or bases, unusual solvents, carcinogens, etc.
The EM Core is not equipped to handle active pathogens and we cannot accept them. Pathogenic samples must be brought in killed and in fixative. We will provide fixatives for any researcher wishing to submit pathogens for EM analysis.
Q) How should I acknowledge the EM Core in my research?
A) Thanks for asking! We greatly appreciate acknowledgements in publications and presentations as a way of letting people know we're here. In fact, for each unique reprint we receive with an acknowledgement of the Core, we give $25 dollars in Core services (not consumables, but microscope, equipment, or staff time).
Something like the following is suggested:
"The authors would like to acknowledge the University of Missouri's Electron Microscopy Core Facility for assistance in preparing and imaging specimens for this research."
Also, acknowledgments of the funding sources for our instruments is also much appreciated. Details are here.
Q) How should I describe the Core's equipment in my research protocols?
A) Here is a list of EM Core equipment with their official names and manufacturers:
Microscopes
JEOL 1400 transmission electron microscope (TEM)
JEOL, LTD., Tokyo, JapanHitachi S4700 Field Emission scanning electron microscope (FESEM)
Hitachi, LTD., Tokyo, JapanFEI Quanta 600F Environmental SEM
FEI Company, Hillsboro, Oregon, USA
Preparation Equipment
Tousimis Auto-Samdri 815 automatic critical point dryer (CPD),
Tousimis Research Corporation, Rockville, MDEmitech K575x Turbo Sputter Coater
Emitech LTD. (Now EM Technologies, LTD.), Kent, EnglandEmitech 950 Turbo Evaporator
Emitech LTD. (Now EM Technologies, LTD.), Kent, EnglandLeica Ultracut UCT ultramicrotomes
Leica Microsystems GmbH, Wetzlar, GermanyLeica EMPact High Pressure Freezer (HPF)
Leica Microsystems GmbH, Wetzlar, GermanyLeica EM AFS Freeze Substitution Unit (FS)
Leica Microsystems GmbH, Wetzlar, GermanyPelco Microwave Sample Processing Systems
Ted Pella, Inc., Redding, CAPelco Low Temperature UV Polymerization Unit
Ted Pella, Inc., Redding, CAAlso, a description of the Core and its services is available here for researchers needing one for grant proposals or other purposes.
Q8) How much does it cost to image a sample in the electron microscopes?
A) Every project is different, depending on the complexity of the protocol and the instruments used. However there are basic preparation procedures that are commonly used, and an estimate for University of Missouri clients can be given based on these.
Please note: Most samples are cheaper than the following estimates! First, less than an hour of scope time may be needed, which would cut the cost accordingly (we have a 30-minute minimum charge). Second, users can easily learn to use the scopes alone, which subtracts the cost of an operator ($35.00 per hour!), from your total. Third, other instruments in the Core, such as the critical point dryer and sputter coater, can be used independently by the researcher at a lower cost than the service rate.
Although we will happily provide soup-to-nuts service, we encourage all of our users to reduce their costs by learning to do as many things as possible themselves. Procedures marked with an * below can easily be done by users at substantial savings.
For one standard biological TEM sample, with one hour of microscope time with operator, the cost at current rates would be as follows:
1) Tissue collection and primary fixation: $14.00
2) Secondary/tertiary fixation and/or dehydration: $16.00
3) Infiltration, embedding and polymerization: $18.00
4) Standard ultramicrotomy: $30.00
5) Contrast staining: $12.25
6) TEM time: $39.00
7) TEM operator*: $35.00
Total: $164.25
Note: TEM image capture on photographic film is available at extra cost.
For one biological SEM sample, the cost would be:
1) Tissue collection and primary fixation: $14.00
2) Secondary fixation and/or dehydration: $16.00
3) Critical point drying*: $28.00
4) Specimen mounting*: $ 8.50
5) Sputter coating*: $17.00
6) S4700 FESEM (600F ESEM) time: $43.00 ($45.00)
7) SEM operator*: $35.00
Total: $161.50 ($163.50)
For our complete pricelist go here.
Q9) When I set a microscope to take an image at a given magnification,
what does that really mean in the final image?A) Not what you might think. We have prepared a handout on this topic. You can download a Word version here
and a PDF file here.Q10) I want to do electron microscopy of cultured cells. How should I prepare my samples for viewing?
A) Cultured cells may be suspended in culture medium or grown on a substrate, such as a cover slip, for preparation for electron microscopy.
Please do not grow the cells directly in the wells of multi-well plates if you want to view them attached to a substrate! They are very difficult to remove from the plates for mounting and insertion into a scanning electron microscope or to prepare them for thin-sectioning for transmission electron microscopy. Instead, please grow the cells on a cover slip. Our preference at the EM Core is to receive the cells on round 13mm Thermonox cover slips, which are plastic, flexible and treated for cell culture. These may be easily prepared for thin-sectioning in different orientations, including horizontal sections from the plane of attachment of the cells serially through to the tops of the cells, or in cross-section from top to attachment plane in one section. This is because the Thermonox cover slips can be sectioned right along with the cells, offering maximum flexibility.
Glass cover slips also work for horizontal sections, but they break easily, leaving behind pieces of glass on the block surface which are difficult to remove and may damage expensive diamond knives.. Also, they are not as suitable for cross-sectioning purposes, since they must be removed completely from the specimen block and the embedded cell layer re-embedded in a second block.
Cells in suspension may be gently spun down and pelleted, then the supernatant removed and replaced with a suitable fixative, followed by resuspension of the cells in the fixative. At this point the cells are stable and may be brought to the EM Core for further processing.
Core staff are happy to consult with you on any questions you may have on preparation of cell cultures for EM or on any other project.. We encourage researchers to contact us before beginning a project, so we may suggest means to achieve the best results most efficiently.