Serum Protein Electrophoresis

A specialized test that separates blood proteins to detect abnormal production patterns.

Serum Protein Electrophoresis

Table of contents

Basic data

Serum Protein Electrophoresis (SPEP) is a laboratory technique that separates proteins in the blood based on their size and electrical charge. It provides a visual distribution of protein fractions such as albumin, alpha, beta, and gamma globulins.

The test is primarily used in clinical contexts to help diagnose and monitor disorders like multiple myeloma, monoclonal gammopathy of undetermined significance (MGUS), and chronic inflammatory or liver conditions. While not typically part of general health screening, it can offer insights when abnormal immune or protein metabolism is suspected.

Category: Lab blood panel

Level: Advanced

Usefulness: Low

Level

Advanced

Best reserved for advanced users under medical supervision or individuals investigating specific clinical symptoms or chronic conditions. Not recommended for general longevity optimization unless clinically indicated.

Usefulness

Low

SPEP offers highly specific data on abnormal protein patterns in the blood — but its application is limited to a narrow set of diagnostic contexts.
Identifies monoclonal gammopathies

Detects M-protein bands in the gamma region, associated with multiple myeloma, MGUS, and other plasma cell disorders.

Assesses chronic inflammation or liver disease

Broad shifts in protein fractions may reflect long-term inflammation, immune dysfunction, or liver synthetic issues.

How it works

The test separates proteins in the serum via an electric field and visualizes them in five distinct bands or zones.
Electrophoretic separation

Proteins migrate through a gel or capillary medium under an electric current, forming identifiable bands.

Pattern interpretation

A trained technician or pathologist reviews the pattern — searching for characteristic spikes, gaps, or shifts.

Measures

SPEP provides a breakdown of serum proteins into fractions — with specific patterns aiding clinical interpretation.
Albumin

The most abundant serum protein — low levels may reflect liver dysfunction, malnutrition, or inflammation.

Alpha-1 and Alpha-2 Globulins

Elevated in acute inflammation or infection. May also be increased in steroid use or nephrotic syndrome.

Beta Globulins

Associated with iron transport and lipid metabolism — altered levels may indicate chronic disease.

Gamma Globulins

Elevated in chronic infections, autoimmune disease, or plasma cell dyscrasias. M-spikes here are a key red flag.

M-protein spike

A sharp peak in the gamma region suggests monoclonal protein production — further testing is often required.

Reliability

SPEP is well-established and clinically validated for detecting abnormal protein production and distribution.
High analytical accuracy

Reliable for identifying monoclonal components and estimating globulin fractions with high reproducibility.

Requires expert interpretation

While results are objective, meaningful insights depend on clinical context and expert pattern recognition.

Limitations

Not a routine screening test — best used in targeted clinical scenarios. Limited usefulness in general wellness tracking.
Low specificity without context

Abnormal results may be seen in many non-specific conditions — requiring further testing to confirm diagnoses.

Not actionable for most users

Changes in protein fractions rarely lead to direct lifestyle or intervention changes without underlying disease.

Frequency

Suggested cadence

Only when clinically indicated. For users with abnormal findings (e.g., M-protein), typically monitored every 6–12 months.

Cost

Typical costs

$30–100 depending on location. Sometimes bundled with immunofixation or additional protein studies.

Availability

Where available

Available in most hospital labs and advanced diagnostic centers. Not typically offered via direct-to-consumer services.

Preparation

How to prepare

Fasting is not always required but may be recommended. Avoid high-protein meals or strenuous activity prior to testing.

Interpretation

Interpretation requires expertise and should be guided by a physician. Patterns, not just values, determine relevance.
M-spike detection

Sharp spike in gamma region suggests monoclonal gammopathy — follow-up includes immunofixation and bone marrow biopsy.

Broad changes

Decreased albumin or altered globulin fractions may reflect chronic inflammation, liver disease, or immune dysfunction.

Alternatives

Immunofixation electrophoresis (IFE)

Used in conjunction with SPEP to confirm and characterize monoclonal proteins. Provides higher resolution identification.

Total protein and albumin/globulin ratio

Less detailed but available in basic blood panels. A/G ratio shifts can hint at similar abnormalities.

FAQ

Should I include SPEP in my general health panel?

No. This is a targeted diagnostic test best reserved for evaluating specific symptoms or doctor-recommended follow-up.

What does a monoclonal spike mean?

It indicates that a single clone of plasma cells is producing large amounts of one antibody — further testing is required to determine if it’s benign (MGUS) or malignant (myeloma).