Conventional karyotyping (G‑banding) looks at all chromosomes at low resolution. It's good for detecting aneuploidies (e.g., Down syndrome) and large rearrangements. FISH uses fluorescent probes to target specific regions — it's faster and can detect smaller abnormalities. The karyotyping market research shows that FISH holds the largest share, but conventional karyotyping is the fastest‑growing, driven by cost pressures in developing countries.
What's the trade‑off? FISH is expensive but targeted. Conventional karyotyping is cheap but labour‑intensive. The karyotyping market trends highlight that the fastest‑growing application is cancer diagnostics, where FISH is used to detect specific translocations (e.g., Philadelphia chromosome in CML).
New techniques: spectral karyotyping (SKY) that paints each chromosome a different colour, and array CGH that detects copy number variations at high resolution.
The bottom line: use conventional karyotyping for screening, FISH for targeted questions, and array CGH for unexplained disorders. Know the strengths and limits of each.
