Histology work flow

Done by: Janice Yeh
Department: Histology

This is my second last department. Mainly observation of the work flow only....wasn't allow to do as i was only posted there for a week.
here we go.
NOTE:
1) The following photos are taken with permission of the department supervisor.
2) Photos below may be abit disgusting. BE PREPARED!

Procedure:
1)When specimens are receieved, they are soaked fully in formalin to remove the smell and for preservation.

2) picture is taken with the measurements by placing a customised ruler beside it. This is to be sent to the clinic/hospital for reference.

Procedures:
1)Once picture is taken, the specimen measurements are measured and taken down on a piece of paper attached to the request form. measurements are taken with a ruler.
2) Specimen is then stained with a black dye so as to cover the outer surface of the specimen to act as a point of reference as to where the cutting point is.
3) Histo-tech also touches and feel the specimen to know the anatomy so as to be able to know what tissues to cut.
4) Observations such as cavity (previously where the tumour was, and has been removed), missing parts such as ovaries must be taken note of and written so as to know that they were not received together with the specimen.

Procedures:
Once the stain is done, cutting of the specimen is done to fit the small orange cases. After the cases are filled, they are place in formalin and kept till the next morning where embedding, microtomy and staining is done.

Embedding
This process is done on a Tissue-Tek. Blocks of tissue are placed on small metal trays and hot wax is filled to cover the tissue. Tissue is pressed down ease the microtomy process by getting even tissue slice. Once the wax is filled, the orange case is pressed on top and it is placed on an ice block to allow cooling. After 10 to 15 minutes, the metal trays are detached from the wax block.

Procedure:

Something that i realise we don't do in school.

We're to put the tissue blocks on ice so as to ensure that the tissues that we cut are intact. I don't exactly know the rationale behind it but is so as to ensure that the wax does not start melting.

Microtomy
The wax block is mainly to give the tissue rigidity as very thin slices are produced. The block is placed on a microtome and thin films of tissues are produced when the blocked is sliced against the blade by a upward-downward motion. The tissue blocks are placed on a ice block before slicing so as to obtain long connected chains of tissue.

Fishing
Once a slice of tissue, or maybe 2 or 5 (depending on the size of the tissue) connected slices of tissue are placed in normal tap water at room temperature. A glass slide is then used to scope up the tissue onto the slide. The slide is then placed in warm water so as to allow the tissue to expand, evening the surface of the tissue for proper staining. Slides are then labelled before loading into the autostainer.


Procedure: Place the slides on a rack and insert into the autostainer.

Procedure: Mount DPX on the slide and place a cover slip over. This is to increase the refracticve index so that cells can be viewed better and clearer under microscope.


Procedure: Place slides on a heater, allowing the DPX to dry as well as for the wax to melt, so that what we view under microscope will only be the cells.

Here is a picture of slides that are stained. as you can see, the first has one tissue, the second slide has 3 tissues and the 3 has 5 tissues. this is determined by the size of the specimen.

Hope that it's clear enough. all the best for MP submission. :D