Name of the Procedure:

Molecular Cytogenetics; Interphase in Situ Hybridization (ISH), Analyze 25-99 Cells

Summary

Interphase in situ hybridization (ISH) is a laboratory procedure used to examine genetic material within cells. This specific test analyzes 25-99 cells to detect genetic abnormalities. It uses fluorescent probes that bind to DNA regions of interest, making it possible to visualize and count these regions under a microscope.

Purpose

This procedure is used to identify genetic abnormalities often linked to cancers and genetic disorders. The goal is to detect duplications, deletions, or rearrangements of DNA segments within cells, which can help in diagnosis, prognosis, and treatment planning.

Indications

• Suspected genetic disorders.
• Diagnosis and monitoring of cancers such as leukemia and lymphoma.
• Prenatal diagnosis of chromosomal abnormalities.
• Assessment of treatment efficacy in cancer patients.

Preparation

• No specific fasting requirements.
• Patients may need to provide a sample of blood, bone marrow, or tissue.
• Previous diagnostic tests may include blood counts, imaging studies, or other genetic tests.

Procedure Description

1. A sample of cells is collected from blood, bone marrow, or tissue.
2. Cells are fixed on a microscope slide.
3. Fluorescent probes specific to the region of interest are applied to the cells.
4. The sample is incubated to allow the probes to hybridize with the matching DNA sequences.
5. Excess probes are washed off, and the slide is examined using a fluorescent microscope.
6. The cells are analyzed, and the number of probe signals in 25-99 cells is counted.

Duration

The procedure typically takes 1-3 hours, but sample analysis and interpretation might take several days.

Setting

The procedure is performed in a specialized laboratory equipped with fluorescent microscopes and other necessary technology.

Personnel

• Clinical laboratory scientists (cytogenetic technologists).
• Pathologists or geneticists for result interpretation.
• Phlebotomists or other medical personnel for sample collection.

Risks and Complications

• Sample collection (blood draw, bone marrow aspiration) may have risks such as infection, bleeding, or bruising.
• Rare possibility of sample contamination or technical issues affecting accuracy.

Benefits

• Accurate identification of genetic abnormalities.
• Aid in diagnosing genetic disorders and cancers.
• Inform prognosis and guide treatment decisions.
• Results usually are available within a few days to a week.

Recovery

• Minimal recovery time for sample collection.
• Patients may resume normal activities immediately after sample collection.
• Follow-up appointments may be required to discuss results and next steps.

Alternatives

• Conventional karyotyping (chromosome analysis).
• Comparative genomic hybridization (CGH).
• Next-generation sequencing (NGS).
• Each alternative has different sensitivity, specificity, time, and cost considerations.

Patient Experience

• Patients may feel slight discomfort during sample collection.
• Anxiety awaiting results is common but can be mitigated by support and counseling.
• Minimal to no discomfort during and after the laboratory analysis.