EMBEDDING

                                                            EMBEDDING

Embedding is the  procedure by which the tissue is made into a block by keeping the
Tissue at the bottom of a  mould filled with molten paraffin -L mould. They consist of                                  L shaped pieces of metal, usually brass, which are laid on glass plate and made into the size desired .


Techniques of embedding
1.    The glass plate is coated well with glycerin.
2.    Metal moulds are coated well with glycerin.
3.    Usually four moulds are kept to form an oblong shape
4.    The mould is filled with appropriate paraffin wax.
5.    The capsule is opened and the tissue is dipped well in molten wax to melt the excess of wax  surrounding the tissue
6.    The temperature of the molten wax should not be very high, as the tissue will get charred .
7.    The tissue is transferred rapidly to the molten wax in the mould with a forceps.
8.    The cutting surface should be kept downwards and the tissue is kept at the bottom of the mould .
9.    If the tissue is slightly bent or if it is multiple, bit, it is pressed with the tip of a piston, which is heated slightly.
10. The label containing the number is inserted on the top of the mould over the tissue .
11.  Ensure that no air bubbles are trapped between the tissue and the base of the mould .
12. 6-8 bits can be embedded in a simple mould depending upon the size of the tissue .
13.  While embedding several bits , the skin which forms on the surface may be broken with a wax forceps.
14. The wax on the tip of the forceps should be removed periodically, by means of heating .
15. Once the skin is formed on the surface , the mould is immersed in a cold water bath .
16. Once the wax is solidified , the L moulds are removed .
17. It is cut into individual blocks along with the label . The wax on the upper surface of the block is trimmed off until the whole tissue is exposed .
18. The label is removed and the sides of the block is trimmed .
19. While trimming some more space should be kept above and below the tissue .
20. Freshly typed label with the number is attached to the sides of the block by using a heated knife tip .
21. The block is then attached to the wooden block using the same heated knife tip .


Orientation of the specimen

Some tissue require special attention while embedding
1.   Skin should be embedded  such that the epithelial surface and the connective tissue should both be on the cutting surface .
2.   Muscle and Appendix biopsies should be embedded so that both longitudinal and transverse sections are obtained .
3.   Tubes should be embedded at right angels so that the lumen is clearly visible .
4.   Bits from GIT should be embedded like cyst wall .




Comments

Post a Comment

Popular posts from this blog

PAS WITH AND WITHOUT DIASTASE

              PAS WITH AND WITHOUT DIASTASE Principle Section must be oxidized with periodic acid to convert 1:2 glycol group to          di-aldehyde in order that they will react with Schiff reagent to produce a colored end product. Glycogen is destroyed by the enzyme diastase which may be obtained from saliva or Malt Solutions Periodic Acid                 -           500mg Distilled Water               -           100 ml The solution is colourless All the glass wares should be properly cleaned and rinsed thoroughly in distilled Water. Procedure 1)    Add 1gm of basic fuchsin into 200 ml of hot distilled  water in a coni...
Read more

MELANIN BLEACH

                        MELANIN BLEACH Melanin is insoluble in almost all organic solvents. Strong oxidizing agent like potassium permanganate will bleach the melanin pigment. Solutions  1) 0.25% Potassium permanganate .                                     Potassium permanganate               -           250mg                                     Distilled water               ...
Read more

LUXOL FAST BLUE

                                      LUXOL FAST BLUE The  method is excellent for staining myelin fibres with good cellular differentiation. Solutions 1)     Luxol fast blue Solution . Luxol fast blue- 1 gm 95% alcohol-100 ml 10% acetic acid-5 ml 2)     Lithium Carbonate 0,05% Aqueous solution 3)     Haematoxylin .  Procedure 1)     Deparaffinise the section in xylene for 10 mts. 2)     Bring the section to water through descending series of alcohol. 3)     Stain in Luxol fast blue overnight at 37°C. 4)       Wash in 95% alcohol then in distilled water 5)     Commence differentiation by immersing sections in lithium carbonate solution for not more than 20 seconds 6)       Differen...
Read more