Tetramethylbenzidine (TMB) substrate concentration in serum/plasma (immunoassay-based measurement)
This test measures the chemical reaction involving TMB, a compound used in certain immunoassays to detect specific proteins or antibodies in your blood. It is often part of a broader assay for markers like inflammation or infection.
["This test helps assess immune response or protein levels indirectly through chemical detection in your blood."]
Key facts at a glance
- LOINC
- 7057-3
- Short code
- TMP SMX Islt Grad strip
- Synonyms
- TMP SMX Islt Grad strip
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- gradient-strip
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is This Test Measuring?
TMB is used in immunoassays to produce a measurable color change when it reacts with enzymes (like horseradish peroxidase) bound to target proteins or antibodies. This reaction generates a signal proportional to the amount of the analyte present. While not a standalone diagnostic test, it’s part of a larger process to quantify substances like cytokines, antibodies, or other biomarkers.
Why Might Your Doctor Order This?
Your doctor may request this test as part of a broader immunoassay panel to evaluate conditions such as autoimmune diseases, infections, or inflammatory processes. It’s not a standalone diagnostic test but contributes to the overall interpretation of your bloodwork.
How Is the Sample Collected?
A blood sample is drawn from a vein, typically in your arm. The sample is processed to separate serum or plasma, which is then analyzed in a lab using an immunoassay method that detects TMB’s reaction.
What Does the Result Mean?
Results are not provided in absolute units here because TMB concentration alone isn’t clinically interpretable without context (e.g., the specific analyte being measured). Your doctor will interpret the results in relation to the full immunoassay results and your clinical symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
TMB substrate measurement is an intermediate step in immunoassays, not a standalone diagnostic test. It helps quantify specific proteins or antibodies but requires correlation with clinical findings, other lab results, and patient history. For example, elevated levels in certain assays may suggest inflammation, infection, or autoimmune activity, but interpretation depends on the full context of your test panel.
Short name
TMB Substrate Level (Serum/Plasma)
Frequently asked questions
How long does it take to get results from this test?
Can I influence the outcome of this test?
The blood draw itself may cause mild discomfort, but the TMB measurement itself is painless. Most people find the process brief and manageable with proper positioning and ice packs for the injection site.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy