Name of the Procedure:

In situ hybridization (ISH)
Commonly known as Fluorescence In Situ Hybridization (FISH)

Summary

ISH is a laboratory technique used to detect specific DNA or RNA sequences in a tissue sample. It involves the use of a fluorescent probe that binds to particular genetic material, allowing visualization under a special microscope.

Purpose

This procedure is utilized to diagnose genetic abnormalities, cancers, and infectious diseases. The main goal is to identify the presence and location of specific genetic material within cells, aiding in accurate diagnosis and treatment planning.

Indications

• Detection of genetic disorders (e.g., Down syndrome)
• Diagnosis and classification of cancers (e.g., breast cancer, leukemia)
• Identification of infectious agents in tissues Patients with suspicious genetic, oncologic, or infectious symptoms may be ideal candidates for this procedure.

Preparation

• No special fasting or medication adjustments are usually required.
• A biopsy or tissue sample must be collected prior to the procedure.
• Patients may need to provide detailed medical history and consent.

Procedure Description

1. A tissue sample is obtained through biopsy.
2. The sample is sent to a laboratory where it is fixed and sectioned onto slides.
3. A fluorescent dye-labeled probe specific to the target DNA/RNA sequence is applied to the sample.
4. The slides are incubated and washed to remove non-specific binding.
5. The sample is then examined under a fluorescence microscope to detect binding of the probe to the target sequence.

Tools used include: biopsy needles, microscopes, and various laboratory reagents and equipment.

No anesthesia or sedation is typically required.

Duration

The laboratory process of ISH usually takes several hours to a few days, depending on the complexity of the test.

Setting

The procedure is conducted in a pathology laboratory. The initial sample collection may be done in a hospital, outpatient clinic, or surgical center.

Personnel

• Pathologists
• Laboratory technicians
• Oncologists or geneticists (depending on the condition being investigated)

Risks and Complications

• Minimal risks associated with the initial biopsy, such as bleeding or infection.
• Lab-related errors are uncommon but may include probe misidentification or technical issues.

Benefits

• Provides precise genetic and molecular information.
• Helps in early and accurate diagnosis.
• Guides targeted therapy and treatment planning. Results are typically available within a few days, leading to timely medical decision-making.

Recovery

• Recovery pertains mostly to the biopsy procedure, which is minimal.
• Patients may resume normal activities immediately unless otherwise instructed.
• Follow-up visits depend on initial biopsy results and subsequent treatment plans.

Alternatives

• Polymerase Chain Reaction (PCR)
• Comparative Genomic Hybridization (CGH)
• Immunohistochemistry (IHC) Each alternative has its pros and cons in terms of specificity, cost, and time efficiency.

Patient Experience

• During the biopsy: slight discomfort or pain, managed with local anesthesia.
• No discomfort during the actual ISH as it is lab-based.
• Patients are usually anxious about awaiting results; supportive care and counseling may be provided.

Pain management after biopsy includes OTC pain relievers and care for the biopsy site to prevent infection.