Repot Histo Slide

Animal Slide Preparation Technique INTRODUCTION : Histology is taken from the Greek words histos, web or tissue and logos. Histology is the study of the tissues of body and how these tissues that have the same function are arranged to constitute organs. The study of the microscopic anatomy of cells and tissues of plants and animals can be performed by examining a thin slice (section) of tissue under a light microscope or electron microscope. The most common procedure used in the study of tissues is the preparation of histological sections that can be studied with the aid of the light microscope. In preparing the slide, there are some techniques that can be used to get the ideal microscope tissue so that the tissue on the slide has the same structure and molecular as it had in the body. Fixation is a chemical process by which biological tissues are preserved from decay, either through autolysis or putrefaction. Fixation terminates any ongoing biochemical reactions, and may also increase the mechanical strength or stability of the treated tissues. Fixation is usually the first stage in a multistep process to prepare a sample of biological material for microscopy or other analysis. Therefore, the choice of fixative and fixation protocol may depend on the additional processing steps and final analyses that are planned. After fixation, the tissues are embedded in the paraffin which involves two main steps: dehydration and clearing, before the tissue is embedded. Then, to studied microscopically, most sections must be stained because it can give color to the tissues as they are most colorless. Generally, stains react in two general ways either they combined directly with the tissue, or they require that the tissues be treated first with an anchoring substance or mordant. Very few stains can be relied upon to color with the desired selectivity or intensity unless carefully controlled. This may be accomplished by stopping at the desired intensity or removing excess with another reagent. Staining is important technique and must be done serially. A microtome is a mechanical instrument used to cut biological specimens into transparent thin sections for microscopic examination. Microtome use steel, glass, or diamond blades depending upon the specimen being sliced and the desired thickness of the sections being cut.

Steel blades are used to prepare sections of animal or plant tissues for light microscopy histology. Glass knives are used to slice sections for light microscopy and to slice very thin sections for electron microscopy. Industrial grade diamond knives are used to slice hard materials such as bone, teeth and plant matter for both light microscopy and for electron microscopy. Gem quality diamond knives are used for slicing thin sections for electron microscopy. There is some precaution when we are using the microtome while doing the slicing. Microtome use extremely sharp blades. So that, all operations with the blade, must be done carefully. There are some operations where the hands must be brought close to the blade. For these procedures hand protection must be worn for example is a cut resistant glove. Then, the knives need to be cleaned. Disposable knives have an anticorrosion coating that must be removed. Diamond paste must be removed from knives when they are sharpened. The smallest silicon particle can ruin the sections. All dust must be removed. Such careful cleaning must bring the hands close to the blade with the attendant risk.

MATERIALS: Mould Forceps Slides and cover slides Microtomes Beakers Normal saline solution 70%, 80%, 95% and 100% Ethanol Bouin’s solution Toluena solution Paraffin solution Xilen 1 Xilen 2 METHODS:

Absolute alcohol + xilen (1:1) Absolute alcohol Alcohol90% Alcohol 80% Alcohol75 % Distilled water Hematoxilin solution 0.5% Hydrochloric solution 0.5% sodium bicarbonate solution Scott’s solution Eosin DPX medium/Balsam Canada

METHOD OF TISSUE PREPARATION: 1. An animal was given to each group. 2. The animal was operated and the organs was taken a.

Liver

b.

Lung

c.

Intestine

d.

Esophagus

e.

Heart

f.

Ovary / testis

g.

Uterus

FIXATION: 1. After the organs were separated from the animal, the organs were rinsed with the normal saline solution that had been prepared. 2. The organs that were rinsed before this were placed into the Bouin’s solution for a night.

DEHYDRATION: 1. After a night, the organs were transferred into the 70% Ethanol solution for 24 hours. 2. Next, the organs were transferred into the 80%, 95% and 100% Ethanol solution for an hour each of the solution.

CLEARANCE 1. The organs were transferred into the Toluena solution for a night. 2. Do the procedure carefully as the solution has an unpleasant smell and dangerous.

EMBEDDED TECHNIQUE: 1. The different organs were put into the different small beakers that contain the paraffin solution (60°C) for 1 hour. 2. The paraffin solution was poured into the large beaker and was replaced by another paraffin solution for another 1 hour. 3. Then, after the paraffin solution was removed from the beaker, the paraffin solution was pour into a mould and put the organ it by the using of forceps carefully. The bubbles are absent in the mould.

4. The solid paraffin was removed from its mould. SLICING TECHNIQUE: 1. The paraffin block was sliced after 5 days. 2. Paraffin block was inserted into the microtome holder. 3. The organ sample was sliced in 5 μm thick. 4. The sliced paraffin tapes were transferred onto the slides that have a few drops of distilled water by using drawing brush. The albumin not the distilled water was drop on the slide for kidney tissue and liver tissue. 5. The slides were put into the 30°C oven. SLIDES COLORING: Harris Haematoxylin-Eosin coloration was used during slides coloring. 1. The slides that contain paraffin tape were taken from the oven. 2. There are 21 solutions in 21 different jars. The slides were put into the solutions according to the duration that was decided.

SOLUTIONS 1. Xilen 1 2. Xilen 2 3. Absolute alcohol + xilen (1:1) 4. Absolute alcohol 5. Alcohol90% 6. Alcohol 80% 7. Alcohol75 % 8. Distilled water 9. Hematoxilin solution 10. 0.5% Hydrochloric solution 11. Water flow 12. 0.5% sodium bicarbonate solution 13. Water flow 14. Scott’s solution 15. Eosin

DURATION(min) 10 5 3 3 3 3 3 3 2 One dip 10 5 10 5 5

16. Alcohol 75% 17. Alcohol 95% 18. Absolute alcohol 19. Absolute alcohol + xilen (1:1) 20. Xilen 21. Xilen

3 3 3 3 10 10

3. Then, DPX medium/Balsam Canada was drop on the slides and was covered by cover slides. 4. Then, the slides were put inside the 37°C oven for one week before observed with light microscope. 5. The slides were labeled.

RESULT:

Liver of frog Magnification power : 10 x 10

Liver of frog Magnification power : 10 x 10

DISCUSSION:

In order to complete this project, a lot of works and problems that we had faced. At the first step, which is the process to dissect the frog, we are not really facing a big problem. The problem while doing the dissecting is because of the size of the frog. The frog is too small, so that there is a little bit difficult for us to dissect the frog. Beside that, we also get only a small organ from that frog. So, we only can make one block for each organ. As a result, we only have four organs from that frog, while the heart of the frog is damaged. During fixation step, dehydration step, and clearance step we are not facing any problems. We just follow the procedure provided. A problem had happened when we are doing the embedded process. Firstly, we have to fill the block with paraffin until 2/3 full. Then, the organ will placed into the block which is 2/3 filled with the paraffin. But, when the organ is put into the block, paraffin at the lowest part of the block is already hardened. So, when the block is fulfilled with the paraffin, the upper part of the paraffin is not as harden as the lower part. As a result, the tissue sample will easily to damage or break when the slicing technique is done. Hence, while embedding the organ, there are present a lot of bubble make this step become difficult to us. When the paraffin is filled into the block, a lot of bubbles are present. Then, when the organ is put into the block, the numbers of bubble is increased. So, we have to break the bubble, but the quantity of the bubble give a problem to us. We are also worried if our organ will damage if we break the bubble. The other problem we have to face during the embedded process is while placed the organ into the block filled with paraffin. The organs are not placed into the block carefully and in also not placed in the right position. So, when we slice the tissue sample, most of the paraffin tapes are damaged. During slicing process, we also faced the problems. We did not get the best paraffin tape because the certain organ should be cut before placing into the block during the embedded process, for example stomach.

The next step is staining. During this process, several tissues are peels away from the slides. This is because the tissue was not really stick to the slides. Then, after staining process is done, we dropped the DPX medium on the slides but we have problem because the bubble are presented. This is because, when we put the cover slide on the slide, we need to press the cover slide smoothly because the cover slide is east to break. So that, to avoid it from broken cause the bubbles still present on the slides. The last step was observing the slide under the light microscope. There are a lot of bubbles on the prepared slide, but we still can differentiate between the cell and the bubble. The best slides are chosen to be submitted.

UNIVERSITI PENDIDIKAN SULTAN IDRIS TBZ 2023 ANIMAL MORPHOLOGY AND HISTOLOGY LAB REPORT (PREPARATION OF ANIMAL'S SLIDE)

NAME : SITI AISHAH BINTI ABDUL LATIFF MATRIC NO : D20081032348 GROUP : A LECTURER : DR HANIZA HANIM MOHD. ZAIN