High Power Field

High Power Field

Unter einem Hauptgesichtsfeld versteht man denjenigen Bereich, der bei insgesamt 400facher Vergrößerung unter dem Mikroskop zu sehen ist. Dies entspricht ungefähr einer Fläche von 5 mm², variiert aber von Mikroskop zu Mikroskop. Insbesondere bei sog. Weitfeldmikroskopen ist bezüglich der Vergleichbarkeit Vorsicht geboten.

Die Vergrößerung setzt sich aus der 40fachen Vergrößerung des Objektivs und der meist 10fachen Vergrößerung des Okulars zusammen. In der Wissenschaft ist die englische Bezeichnung High-Power-Field (Abkürzung HPF) dabei deutlich geläufiger.

Anwendung findet dieser Begriff z. B. in der Befundung histologischer Schnitte, z. B. 10 Mitosen auf 50 Hauptgesichtsfelder. Hierzu wird ein Hauptgesichtsfeld eingestellt, alle Mitosen gezählt und das Präparat zum nächsten HPF verschoben. Nun beginnt der Vorgang von neuem bis 50 HPF ausgezählt sind. Die Anzahl der Mitosen liefert dann einen Hinweis auf die Bösartigkeit mancher Krebsarten wie beispielsweise Gastrointestinaler Stromatumoren.[1]

Quellen

  1. Fletcher CD, Berman JJ, Corless C, Gorstein F, Lasota J, Longley BJ, Miettinen M, O’Leary TJ, Remotti H, Rubin BP, Shmookler B, Sobin LH, Weiss SW.: Diagnosis of gastrointestinal stromal tumors: a consensus approach. Hum Pathol 33: 459– 465 (2002)

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