Skip to main content
Sign In

Denver Genetic Laboratories

Mitochondrial Respiratory Chain Enzyme Assay - Skin Fibroblasts

Clinical Test Information - UCD Biochemical Genetics Laboratory


CPT Codes:

82657 x 6 (six assays are performed)
88233 x 1
88240 x 1


Monday - Friday, 0800 - 1700.

Turnaround Time:

2 - 3 months (depending on growth rate of cultured cells).

Minimum Volume:

Two T-25 flasks of confluent fibroblasts, with plug-seal caps, completely filled with media. Fibroblasts must be mycoplasma-free.

Specimen Handling:

Send flasks in a Styrofoam box at room temperature. Please include passage number (if known).
A requisition form for mitochondrial enzyme assay must be enclosed. Please complete both
pages of the requisition form for mitochondrial enzyme assays.

Interpretive Reference Range (5th and 95th percentiles):

Fibroblasts (in nmol/min per mg protein):

           Complex 1: 48.9–120.1

           Complex 2: 144.4-349.2

           Complex 3: 7.92-30.38

           Complex 2+3: 102.1 -210.6

           Complex 4: 2.13 -6.84

           Citrate synthase: 245.4 -540.4

(Ratios of complex activities over citrate synthase and over complex 2 are provided. Subject to interpretation.)


Diagnosis of mitochondrial respiratory chain diseases


Spectrophotometric enzyme assays