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Official Description

Protein; Western Blot, with interpretation and report, blood or other body fluid, immunological probe for band identification, each

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The CPT® Code 84182 refers to the Western Blot procedure, specifically designed for the detection of proteins in blood or other body fluids. This analytical technique, also known as protein immunoblotting, is crucial for identifying specific proteins that may be present in various biological samples. The process begins with the separation of proteins through gel electrophoresis, a method that utilizes an electric field to move proteins based on their size and charge. Once separated, these proteins are transferred onto a membrane, typically made of nitrocellulose or polyvinylidene fluoride (PVDF). This membrane serves as a solid support for the proteins, allowing for further analysis. To identify the proteins of interest, specific antibodies that target these proteins are applied to the membrane. The use of an immunological probe is a key feature of this procedure, as it enables the precise identification of protein bands corresponding to the target proteins. Each band identified represents a specific protein, and the interpretation of these results is included in the service provided under this code. The code 84182 is reported for each immunological probe used in the analysis, ensuring that the complexity and detail of the testing are accurately captured in the coding process. This comprehensive approach not only aids in the diagnosis of various conditions but also supports the overall understanding of protein expression in clinical settings.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The Western Blot procedure, represented by CPT® Code 84182, is indicated for the detection and identification of specific proteins in blood or other body fluids. This technique is commonly utilized in various clinical scenarios, including:

  • Diagnosis of Infectious Diseases The Western Blot is often employed to confirm the presence of specific antibodies related to infections, such as HIV, Lyme disease, and other viral or bacterial infections.
  • Assessment of Autoimmune Disorders This procedure can be used to identify autoantibodies that may indicate autoimmune conditions, helping in the diagnosis and management of diseases such as lupus or rheumatoid arthritis.
  • Protein Expression Studies Researchers and clinicians may use this technique to study protein expression levels in various conditions, aiding in the understanding of disease mechanisms and potential therapeutic targets.

2. Procedure

The Western Blot procedure involves several critical steps to ensure accurate detection and identification of proteins. The steps are as follows:

  • Step 1: Sample Preparation The process begins with the collection of a biological sample, typically blood or another body fluid. The sample is then processed to extract proteins, which may involve centrifugation and other preparatory techniques to isolate the proteins of interest.
  • Step 2: Gel Electrophoresis The extracted proteins are subjected to gel electrophoresis, where they are separated based on their size and charge. This step is crucial as it allows for the resolution of individual proteins within the sample, creating distinct bands that can be analyzed further.
  • Step 3: Transfer to Membrane After electrophoresis, the separated proteins are transferred onto a nitrocellulose or PVDF membrane. This transfer is typically achieved through an electric current that moves the proteins from the gel to the membrane, where they become immobilized for subsequent analysis.
  • Step 4: Application of Immunological Probes Specific antibodies that target the proteins of interest are applied to the membrane. These antibodies bind to their corresponding proteins, forming complexes that can be detected. The use of immunological probes is essential for identifying the specific bands on the membrane.
  • Step 5: Detection and Interpretation Following the application of the antibodies, various detection methods are employed to visualize the protein-antibody complexes. This may involve the use of enzyme-linked secondary antibodies or fluorescent tags. The resulting bands are then analyzed, and an interpretation report is generated, detailing the presence and identity of the proteins detected.

3. Post-Procedure

After the Western Blot procedure is completed, the results are compiled into a detailed report that includes the interpretation of the protein bands identified. Clinicians may use this report to make informed decisions regarding diagnosis and treatment options. There are typically no specific post-procedure care requirements for patients, as the procedure is performed on samples rather than directly on individuals. However, it is essential for healthcare providers to communicate the results to patients and discuss any necessary follow-up actions based on the findings. Additionally, proper documentation and coding of the procedure are crucial for accurate billing and reimbursement.

Short Descr PROTEIN WESTERN BLOT TEST
Medium Descr PROTEIN WESTRN BLOT BLOOD/OTH FLU IMMUNOLOGICAL
Long Descr Protein; Western Blot, with interpretation and report, blood or other body fluid, immunological probe for band identification, each
Status Code Active Code
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 6 - Laboratory Physician Interpretation Code
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
CLIA Waived (QW) No
APC Status Indicator Conditionally packaged laboratory tests
Type of Service (TOS) 5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS) T1H - Lab tests - other (non-Medicare fee schedule)
MUE 6
CCS Clinical Classification 233 - Laboratory - Chemistry and Hematology
90 Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
91 Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient.
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
GZ Item or service expected to be denied as not reasonable and necessary
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
GA Waiver of liability statement issued as required by payer policy, individual case
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
Date
Action
Notes
2011-01-01 Changed Short description changed.
2005-01-01 Changed Code description changed.
2004-01-01 Changed Code description changed.
1993-01-01 Added First appearance in code book in 1993.
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