Specimen Nr. 01C

Specimen:

Hyaline cartilage, Trachea (Human being)

Staining:

H&E

Magnification:

128x

Important structures :

1.	Artificially empty chondron
2.	Chondrocyte surrounded by a strongly basophilic stained territorial (capsular) matrix
3.	Chondrocyte in cartilage lacuna (artifact)
4.	Intensely basophilic stained territorial (capsular) matrix of chondrocyte

Die unterschiedlich großen Knorpelzellen sind in kleinen Gruppen, den Chondronen, zusammengelagert. Bei manchen erscheint das Zytoplasma hell. Bei anderen ist die Zelle von der extrazellulären Matrix abgelöst, so daß eine sog. Knorpelhöhle entsteht. Beides sind durch Fixierung und Paraffineinbettung hervorgerufene Artefakte. Im sog. Knorpelhof um die Chondrone bzw. Chondrozyten ist die extrazelluläre Matrix stärker basophil angefärbt.

Legende:

	Artificially empty chondron
	Chondrocyte surrounded by a strongly basophilic stained territorial (capsular) matrix
	Chondrocyte in cartilage lacuna (artifact)
	Intensely basophilic stained territorial (capsular) matrix of chondrocyte

Hematoxylin and Eosin (H&E)

H&E is the most common survey stain, which shows cell nuclei and cytoplasmatic components.

Structures	Colour
Nuclei	blue
Cytoplasm	pale red
Connective-tissue fibres - Collagen - Reticular - Elastic	red - pale rose to red
Muscle tissue	red
Erythrocytes	red-orange

Dyes:

Hematoxylin

(e.g. hemalaun, Weigerts or Heidenhains iron-hematoxylin)
Hematoxylin is a positively charged dye (at low pH values). It therefore colors negatively charged (basophilic) structures blue, like the DNA of nuclear chromatin, the RNA of rough endoplasmatic reticulum, and the acidic glycosaminoglycans of hyaline cartilage.
Hematoxylin used in the preparation of iron varnish is Weigerts or Heidenhains iron-hematoxylin and in the preparation of aluminum varnish is hemalaun.

Eosin

Eosin is a negatively charged dye used for counterstaining. It stains all remaining structures different shades of red (acidophilic).

Thiazinrot

Thiazinrot behaves similar as eosin.

Die extrazelluläre Matrix des hyalinen Knorpels enthält 2 Hauptkomponenten, die von den Chondrozyten synthetisiert werden:

Kollagene Fibrillen (Typ-II-Kollagen), die mechanische Festigkeit bewirken
Glykosaminoglykane (GAG) und Proteoglykane, die einer Verformung durch Druckkräfte widerstehen

Daß die extrazelluläre Matrix des hyalinen Knorpels nicht "faserig", sondern homogen erscheint, wird durch die Maskierung der kollagenen Fibrillen durch Chondroitinschwefelsäure, ein GAG, bedingt.

HistoNet2000 - Help

1. Organization of the screen surface

Right side: histologic specimen
Left side: information about the specimen (above) and general program functions (below)

2.Histologic specimen

Pull the mouse across the histologic specimen for training purposes. A small square with exclamation marks (dynamic labels) will appear where there is an important structure. You should then decide what structure this could be. To check your result, simply click the appropriate square, and the correct label will appear. The option “marked” allows you to see all labels for all structures simultaneously. These can be removed by clicking “unmarked”. This reactivates the dynamic labels.

3. Complementary information

Info: general information about the specimen, as well as a list of the dynamic labels
Drawing: schematic drawing of the specimen
Staining: information about the staining method for this specimen
Knowledge: short texts with basic histologic information, presently deactivated

4. General Program Functions

Home: returns you to the “start” page
Tutor: how to contact the HistoNet Team
Help: Instructions for Use appear
Exit: closes down the HistoNet program
Boxes: goes back to the other specimen of a topic
VM: provides virtual microscopy

We hope you will enjoy working with HistoNet2000 and learn a lot from it!