Test Catalog

Test Id : FETCE

Mitochondrial Respiratory Chain Enzyme Analysis (ETC) - Skin Fibroblasts

Method Name
A short description of the method used to perform the test


NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Electron Transport Chain Enzymes

Lists additional common names for a test, as an aid in searching

Cytochrome c Oxidase Deficiency

Electron Transport Chain Enzymes

Leigh Syndrome due to Cytochrome c Oxidase Deficiency

Mitochondrial Respiratory Chain Complex I Deficiency (mitochondrial genes)

Mitochondrial Respiratory Chain Complex I Deficiency (nuclear genes)

Mitochondrial Respiratory Chain Complex I Deficiency

Mitochondrial Respiratory Chain Enzymes

Respiratory Chain Complexes

Specimen Type
Describes the specimen type validated for testing


Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Cultured Fibroblasts

3 T-25 flasks(s) filled to neck with culture media. Maintain sterility and forward promptly at ambient temperature.


Complete and submit with specimen:

1.     Baylor Mitochondrial request form.

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis NA
Lipemia NA
Icterus NA
Other NA

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Fibroblasts Ambient

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

A final report will be attached in Mayo Access.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

Kirby DM, Thorburn DR, Turnbull DM, Taylor RW. Biochemical assays of respiratory chain complex activity. Methods Cell  Biol, 2007; 80:93-119.

Trounce, I.A., Kim, Y.L., Jun, A.S., Wallace, D.C. Assessment  of mitochondrial oxidative phosphorylation in patients muscle biopsies, lymphoblasts  and transmitochondrial cell lines. Methods Enzymol, 1996. 264, 484-509.

Gellerich, F.N. et al. (2004) The problem of interlab variation in methods mitochondrial disease diagnosis: enzymatic measurement of respiratory chain complexes. Mitochondrion 4, (427-439)

Enns,  G.M. et al. (2005) ReIatonship of primary mitochondrial respiratory chain· dysfunction to fiber type abnormalities in skeletal muscle. Clin.  Genet. 66: 337-346. Bernier, FP, Boneh A, Dennett  X, Chow  CW, Cleary MA, Thorburn DR (2002) diagnostic criteria for respiratory chain disorders in adults and children.  Neurology 59, 1406-11.

Walker UA, Collins S, Byrne E (1996) Respiratory chain encephalomyopathies: a diagnostic classification. Eur Neurol 36, 260-267.

Method Description
Describes how the test is performed and provides a method-specific reference

The electron transport chain enzymes were assayed at 30 C using a temperature-controlled spectrophotometer.  Each assay is performed in duplicate.  The activities of complex I (NADH:Ferricyanide dehydrogenase), complex II (succinate- dehydrogenase), complex I+III (NADH:cytochrome c oxidoreductase), complex II+III (succinate:cytochrome c reductase) and complex IV (cytochrome c oxidase) were measured using different electron acceptors/donors. The increase or decrease of cytochrome c at 550 nm was measured for complex I+III, II+III, or complex IV. The activity of complex I was measured-by following the oxidation of NADH at 340 nm. For complex II, the reduction of 2, 6-dichloroindophenol (DCIP) at 600 nm was measured. Citrate synthase is used as a marker for mitochondrial content. Enzyme activities are normalized against citrate synthase (CS) activity when CS activity is greater than 1 standard deviation above or below the control mean. The second figures in parentheses represent data after normalization if it has been performed. The interpretation of the results is done on the assumption that the specimen has been handled properly.

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Upon receipt

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

42 to 45 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Baylor Medical Genetics Laboratories

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CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

84311 x 6

82657 x 6



LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
FETCE Electron Transport Chain Enzymes Not Provided
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
Z1751 Electron Transport Chain Enzymes Not Provided

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports