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Test Code EM Electron Microscopy

Shipping Instructions

Whole blood specimens must arrive within 48 hours of draw.

Necessary Information

1. A completed Patient Information Sheet is required for all Electron Microscopy Consultations (see Special Instructions)

2. Tissue source required for testing to be performed.

Specimen Required

Tumor biopsies must be accompanied by a history, hematoxylin and eosin-stained slides, and a paraffin block.


Collect specimen according to the instructions in Electron Microscopy Procedures of Handling Specimens for Electron Microscopy in Special Instructions. Do not place on ice, dry ice, or freeze.


Submit only 1 of the following specimen types:


Supplies: Electron Microscopy Kit (T660)

Specimen Type: Fixed wet tissue

Container/Tube: Electron Microscopy Kit (T660) or leak-proof container

Specimen Volume: Entire specimen

Additional Information: PATHC / Pathology Consultation may be added if deemed necessary by the reviewing pathologist.


Specimen Type: Whole blood (Neuronal Ceroid Lipofuscinosis-NCL only)

Container/Tube: Electron Microscopy Kit (T660), green top (sodium heparin), or yellow top (ACD [solution B])

Specimen Volume: 5 mL

Collection Instructions: Do not transfer blood to other containers.


1. Electron Microscopy Patient Information in Special Instructions

2. Electron Microscopy Procedures of Handling Specimens for Electron Microscopy in Special Instructions

3. Pathology/Cytology Information (T707) in Special Instructions

4. If not ordering electronically, complete, print, and send a Pathology Test Request Form (T246) with the specimen (

Secondary ID


Useful For

Identifying tumor


Diagnosing medical disorders such as storage diseases, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and primary ciliary dyskinesia

Testing Algorithm

For nontumorous renal specimens, see RPCWT / Renal Pathology Consultation, Wet Tissue for Electron Microscopy.

For platelet disorders, see PTEM / Platelet Transmission Electron Microscopic Study.

For muscle specimens, see MPCT / Muscle Pathology Consultation.

For CADASIL genetic mutation testing on blood, contact Mayo Medical Laboratories.

Method Name

Electron Microscopy

Reporting Name

Electron Microscopy

Specimen Type


Specimen Minimum Volume


Specimen Stability Information

Specimen Type Temperature Time
EM Ambient (preferred)

Reject Due To








Muscle tissue, Fat pads

Clinical Information

Crucial diagnostic information for the study of human disease may be provided by transmission and scanning electron microscopy. Often information of a confirmatory nature or of educational value to the clinician and pathologist can be obtained by this procedure.


In recent years, the technology involved in electron microscopy has progressed to the point where methods have become standardized and the instrumentation routine. The electron microscope is a fundamental tool in medical diagnostic and cellular pathobiological investigations, because it is at this instrument's level of resolution that most structural correlations with function and metabolism are visible.

Reference Values

An interpretive report will be provided.


The images and case histories are correlated and interpreted by a pathologist who is an expert in the field of the suspected diagnoses.


Results will be provided by telephone. If requested, representative images showing diagnostic features will be sent.

Clinical Reference

Damjanov I: Ultrastructural Pathology of Human Tumors. St. Albens, VT, Eden Press, Vol 1, 1979; Vol 2, 1980

Day(s) and Time(s) Performed

Monday through Friday; Varies

Analytic Time

4 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test uses a standard method. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
EM Electron Microscopy In Process


Result ID Test Result Name Result LOINC Value
71033 Interpretation 50595-8
71034 Participated in the Interpretation No LOINC Needed
71035 Report electronically signed by 19139-5
71037 Material Received 81178-6
71788 Case Number In Process