- What This Cheat Sheet Covers (and What It Doesn't)
- The Exam at a Glance
- Blueprint Weights in One Table
- Domain 1: Instrumentation and Electron Optics
- Domain 2: Sample/Tissue Processing
- Domain 3: Sectioning and Staining
- Domain 4: Special Techniques and Imaging
- Domain 5: General Chemistry, Math and Safety
- The Separate Practical Examination
- Validity and Reinstatement: Where the Sources Disagree
- A Domain-Ordered Review Schedule
- Frequently Asked Questions
- CEMT is the Microscopy Society of America's biological transmission electron microscopy credential, not a general SEM credential.
- The written exam is objective (multiple-choice and true-false), runs three hours, and requires an 80% to pass.
- Five content areas are weighted approximately 25/25/15/20/15; the issuer calls these approximate, not item quotas.
- You must pass the written exam before submitting the separate practical: three independently prepared biological samples.
What This Cheat Sheet Covers (and What It Doesn't)
This page condenses the must-know facts for the Certified Electron Microscopy Technologist credential, awarded through the Microscopy Society of America (MSA) and administered by the MSA Certification Board. It is organized around the five written-examination content areas in the official MSA brochure, because that outline is the most reliable guide to what the written test samples.
Two boundaries matter. First, this is a review aid, not a substitute for the issuer's own documents. Second, the written exam and the practical exam are separate assessments, and a cheat sheet or practice bank can only help with the first. If you are brand new to the credential, start with What Is CEMT Certification? for the big picture, then return here for the fact-dense review.
The Exam at a Glance
| Item | What to Know |
|---|---|
| Credential | Certified Electron Microscopy Technologist (CEMT) |
| Certifying body | Microscopy Society of America; exams administered by the MSA Certification Board |
| Scope | Biological transmission electron microscopy (TEM) |
| Written format | Objective items, including multiple-choice and true-false |
| Written time limit | Three hours |
| Written passing score | 80% |
| Item count / scored vs. unscored split | Not verified; don't rely on third-party claims |
| Practical exam | Separate; three independently prepared biological samples; average mean score of 80 required |
| Sequence | Pass the written exam before submitting the practical |
| Exam cycles | Two per year, with separate application, written-exam and practical-submission deadlines |
| Renewal | Ten-year renewal described by both MSA sources |
Eligibility rests on qualifying education and/or occupational experience. The details are covered in CEMT Requirements 2026: Eligibility, Prerequisites & How to Qualify, and the calendar logistics are in CEMT Exam Dates 2026: Testing Windows, Deadlines & Scheduling. Fees are best confirmed against the current MSA application; our CEMT Certification Cost 2026 breakdown explains what to look for.
Blueprint Weights in One Table
The MSA brochure lists five weighted content areas. MSA describes the percentages as approximate, so they signal emphasis, not guaranteed numbers of questions per area.
| Domain | Approx. Weight |
|---|---|
| 1. Instrumentation including electron optics | 25% |
| 2. Sample/Tissue processing (fixations, resin chemistry etc.) | 25% |
| 3. Sectioning and Staining | 15% |
| 4. Special techniques (Immuno, shadowing, cryo, etc.) and imaging | 20% |
| 5. General: chemistry, safety | 15% |
A quirk worth knowing: the detailed syllabus has six headings, because "Digital Imaging/Power Point" and "Special techniques" appear separately. Both fold into the single fourth weighted area. There is no sixth weighted domain. Our CEMT Exam Domains 2026: Complete Guide to All 5 Content Areas walks through each in more depth.
Domain 1: Instrumentation and Electron Optics (≈25%)
The TEM itself
Expect questions on how the microscope works and how you keep it working well.
- TEM operation: illumination, imaging systems, alignment and focusing
- Maintenance and test specimens
- Astigmatism, resolution and calibration
- Contamination: sources and prevention
Supporting instruments
This domain extends well beyond the column. Don't skip the "boring" equipment.
- SEM general principles and operation (supporting knowledge within a biological TEM credential)
- Ultramicrotomes, knifemakers and light microscopes
- Vacuum evaporation and sputter coating
- Pumps: mechanical, diffusion, turbomolecular and ion; plus vacuum gauges
- Lab equipment: incubators, ovens, balances, pH meters, osmometers, centrifuges
- Digital photographic techniques
The pump list is a classic area where candidates know one type well and are surprised by the others. Know what each pump does, where it sits in the vacuum chain, and which gauge reads which pressure range.
Domain 2: Sample/Tissue Processing (≈25%)
This is tied with instrumentation for the heaviest weight, and it is the domain where benchwork experience pays off most.
Fixation
- Fixatives and reagents: glutaraldehyde, paraformaldehyde, OsO4, KMnO4
- Buffers: phosphate, cacodylate, PIPES, HEPES
- Variables that change fixation outcomes: concentration, time, temperature, pH, osmolarity, additives and penetration
- Delivery methods: immersion, perfusion and vapor fixation
- Criteria for good fixation, washing, and en bloc staining
Dehydration, infiltration and embedding
- Dehydration agents: ethanol, acetone, ethylene glycol, propylene oxide, acetonitrile
- Infiltration, embedding and polymerization
- Plastic families: acrylic, polyester and epoxy, with their catalysts, hardeners and plasticizers
- Embedding approaches: capsule, flat, cell-culture and vacuum embedding
A useful way to study this domain is by "what goes wrong": poor penetration, extraction, shrinkage, incomplete polymerization. Questions often test whether you can connect a symptom to a cause such as buffer osmolarity, fixation time, or infiltration schedule.
Domain 3: Sectioning and Staining (≈15%)
Cutting
- Block trimming, facing and remounting
- Glass knives: breaking, inspection and troughs
- Diamond knife use
- Thick-section collection and mounting
- Thin sections: orientation, flotation, flattening, collection, and thickness judged by interference color
- Section problems and the factors behind section quality
Grids and support films
- Grid types and cleaning
- Coatings: Formvar, Butvar, collodion and carbon
Stains
- Thick-section stains: Toluidine blue-O, methylene blue, Paragon, azure II, Giemsa
- Thin-section stains: uranyl acetate, lead citrate, phosphotungstic acid, osmium, ruthenium, silver
- Staining quality and common artifacts
Remember that this is only about 15% of the written blueprint, but sectioning skill also drives your practical submission, so the knowledge does double duty.
Domain 4: Special Techniques and Imaging (≈20%)
This combined area merges the syllabus sections for digital imaging and special techniques.
Imaging
- Imaging principles and image processing
- Computers, labels, magnification and scale bars
Specialized preparation methods
- Negative staining
- Shadow casting and replication
- Cytochemistry and immunolocalization
- High-pressure freezing and freeze substitution
Domain 5: General Chemistry, Math and Safety (≈15%)
Core background
- Basic cytology, cell morphology and ultrastructure
- Solvents and solutions: normality, molarity, percentages; acids, bases and salts
- Clean glassware and distilled/deionized water
- Metric system, trigonometry and measurement
- Safety: radiation, chemical, biological and fire
Don't underestimate this area. Solution-making arithmetic and safety knowledge appear in everyday lab work, and the questions tend to be answerable if you've done the calculations by hand rather than just recognizing formulas. Safety is especially relevant given the reagents in Domain 2 (osmium tetroxide, uranyl acetate and others).
The Separate Practical Examination
The practical is a distinct assessment with its own requirements:
- Three independently prepared biological samples
- Submission of sections, grids, images and methods
- A signed Pledge of Independent Workmanship
- An average mean score of 80 required
Two cautions. The practical scoring does not apply to the written test, and the written-exam domain weights do not apply to the practical. And a written practice bank cannot complete or replace the laboratory assessment, so follow MSA's full current instructions for practical submissions and plan your bench time early. If you're still deciding whether the effort is worthwhile, see Is the CEMT Certification Worth It? and CEMT Jobs for where the credential matters in hiring, and CEMT Salary Guide 2026 for earnings context.
Validity and Reinstatement: Where the Sources Disagree
MSA's two public sources do not fully agree on certification maintenance, and the written-exam outline doesn't resolve it.
| Topic | Program Webpage | Linked Brochure |
|---|---|---|
| Initial validity | Award calendar year plus the following year | One calendar year |
| Lapse / reinstatement | Reinstatement within three years with relevant-work documentation | One-year reinstatement; re-examination after two or more years |
| Renewal | Both describe a ten-year renewal | |
Use the current program webpage as your reference for current policy, and confirm your individual situation with MSA before assuming anything about a lapse. Also note that the publicly linked 2026 brochure carries an internal metadata title of "Editing Draft." That is a file-property quirk, not evidence of a separately announced exam revision, and the listed 2026 exam cycles are scheduling dates, not a new syllabus effective date.
A Domain-Ordered Review Schedule
Rather than generic pacing, sequence your review to follow how the lab workflow runs and how the blueprint is weighted. Adjust the timeline to your own exam date.
Domain 5 foundations
- Solution math, molarity/normality, metric conversions, and safety rules
- These skills underpin every later domain
Domain 2: processing
- Fixatives, buffers, dehydration agents, resin families
- Build "symptom to cause" tables for fixation and infiltration problems
Domain 3: sectioning and staining
- Knives, grids, support films, interference colors, stain lists
Domain 1: instrumentation
- Electron optics, alignment, astigmatism, vacuum system and pumps
Domain 4: special techniques and imaging
- Negative staining, shadowing, immunolocalization, HPF/FS, scale bars
Mixed review
- Timed sets across all domains, weighted toward your weakest areas
Why this order? Domain 5 math and safety supports everything else, and the two 25% domains get the most total hours. For a fuller plan, see the CEMT Study Guide 2026, and when you're ready to test yourself against exam-style items, the CEMT practice tests let you drill by content area. If you're calibrating how much preparation to commit, How Hard Is the CEMT Exam? and CEMT Pass Rate 2026: What the Data Shows give honest context. For more on the credential itself, see What Is CEMT?.
Key Takeaway
Spend your hours in proportion to the blueprint: instrumentation and tissue processing together carry roughly half the written exam. Then use targeted practice questions to find which of the five content areas needs another pass.
Frequently Asked Questions
Here, CEMT means Certified Electron Microscopy Technologist, the Microscopy Society of America credential for biological transmission electron microscopy. The acronym is used by other unrelated credentials, which this article does not cover. See What Does CEMT Stand For? for more.
The written examination allows three hours and requires an 80% to pass. It is objective, including multiple-choice and true-false items. The exact item count and scored/unscored split are not verified in MSA's public materials.
No. MSA describes the weights (25%, 25%, 15%, 20%, 15%) as approximate, so treat them as guidance on emphasis rather than guaranteed item quotas for each content area.
Pass the written examination first. Only then can you submit the separate practical, which consists of three independently prepared biological samples, a signed Pledge of Independent Workmanship, and an average mean score of 80.
The program webpage and the linked brochure conflict on initial validity and reinstatement. Use the current program webpage for current policy and confirm your individual case with MSA directly, since the written-exam outline doesn't settle it.