Practical 3:formalin ethyl acetate concentration technique
Objective: to identify the type of parasite that can be identify by the formalin ethyl acetate
Material: centrifuge tube,feces specimen,centrifuge,formalin ethyl acetate,
Procedure :
1. The centrifuge tube were prepared,the filtrated feces were added into it for 15ml
2. The tube were centrifuge for 1500 rpm about 2minutes
3. After centrfifuged ,it were added with 7-8ml formalin resuspended and leaved for 10 minutes,before that it must sediment only inside the tube,
4. The 3-4ml ethyl acetate were added after that and shaked vigorously,
5. Centrifuged for 1500 rpm for 2 minutes and the 4 layer were presented,
6. The bottom of the layer were direct mounted and obsereved on the slide
Discussion
The concentration technique were used for the identification of the intestinal nematode ,the concentration technique were used to make the identification of the nematode can be recognize more effectively,it may affected the trphozoite of the nematode to be recognize,some of the concentration technique were the floatation technique and other were sediment,the debris can be removed effectively by the concentration technique to observe the parasite .the centrifuge were used in this experiment to separate the low specific gravity with higher specific gravity,it commoly used for the feces the preservative with formalin.
The purpose of the reagent in this experiment like the ethyl-acetate were Less flammable and more stable than ether,Less combustable than ether,Greater numerical recovery of parasites (especially with Taena sp, H. nanaand A. lumbricoides, and many cysts). But the Disadvantages of this reagent were Thicker deposit and A less effective lipid extraction agent therefore Triton-X must be added into the solution.the formalin are used in this experiment as the preservative and the ethyl acetate were the best technique in the feces preservative with the formalin,
The precaution that needed to be done in this experiment are make sure the amount of the feces are in exact amount,the sediment must be remain in good condition so the wet mount can be done correctly and no error were done,parasite can be identify exactly.the time for the centrifugation were correctly so the layer formed are exactly 4 layer,if not 4 layer from test are make again.the feces also must be in accurate amount so the test are good result,
The eggs are oval or elliptical, measuring 60 µm by 40 µm, colourless, not bile stained and with a thin transparent hyaline shell membrane. When released by the worm in the intestine, the egg contains an unsegmented ovum. During its passage down the intestine, the ovum develops and thus the eggs passed in feces have a segmented ovum, usually with 4 to 8 blastomeres. As the eggs of both Ancylostoma and Necator (and most other hookworm species) are indistinguishable, to identify the genus, they must be cultured in the lab to allow larvae to hatch out. If the fecal sample is left for a day or more under tropical conditions, the larvae will have hatched out, so eggs might no longer be evident. In such a case, it is essential to distinguish hookworms from Strongyloides larvae, Laboratory diagnosis depends on finding larvae in stool, sputum or duodenal aspirates. The first stage rhabditiform larvae measure approximately 250 long by 20 wide.
They have a bulbed oesophagus and a short buccal cavity. In an old specimen, rhabditiform larvae of S. stercoralis must be differentiated from those of hookworm which have a longer buccal cavity. The third stage or filariform larva is approximately 500 long and has a notched tail compared with that of hookworm which is sheathed and has a long slender tail.
Conclusion
The ethyl acetate concentration technique can be identify the hookworm and the strongliloides strerocralis nematode.it were taken at the bottom of the tube and direct wet mount.
Question
1. What type of feces can be used for the ethyl acetate?
For the best result were the feces with the formlain preservative
2. Can other parasite can be found with ethyl acetate?
Yes ,like the giarda lamblia.and E.coli
3. What happen if the ethyl acetate direct contact with flame?
It do not burn.because it not volatile and not flammable
References
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