Abstract

ABSTRACT

The aim of the first experiment which is the use of microscopy is to use the microscope in a correct manner and also to examine the specimen sample under the microscope. For the first experiment, two animal cell and two plant cell were used in the experiment. The sample specimen chosen were chicken and fish for animal cell and onion and leave for the plant cell. The specimen were prepared and put on the lass slide and is covered usin a cover slip. The specimen then is viewed under the liht microscope usin the appropriate manification. The main difference !etween a plant cell and an animal cell is  plant cell contains a riid cell wall while animal cell does not. The second experiment is the stain and identify the specimen iven in the la!oratory. Two Two specimen were used as sample for this ram stainin experiment which were  E. coli and yeast. Both of the specimen is transferred to the lass slide with an inoculation loop. The ram stainin processes uses crystal violet, methylene !lue, iodine, decolouri"er, and safranin. From the experiment it is known that E. coli is ram neative !ecause it was stained pink and yeast is ram positive which after the ram stainin experiment the colour purple .

#.$ %B&'CT()'S '*+'R('-T # T/' 0S' %F (CR%SC%+' i. To learn the correct method of usin liht microscope ii. To examine specimen samples under liht microscope

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i. ii.

To choose suita!le stainin aent for inspection of different types of specimens To prepare slide usin 2ram stainin methods

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A microscope is an optical instrument for viewin o!6ects that are too small to !e seen  !y naked eye. The science of investiatin small o!6ects usin such an instrument is called microscopy. The term 7microscopic7 means minute or very small, not visi!le with the eye unless aided !y a microscope. The most common microscope used in la!oratories is the liht microscope. The liht microscope has the manification of 8x, #$x, and 8$x.

The 2ram stain is the most important stainin procedure in micro!ioloy. (t is used to differentiate !etween ram positive oranisms and ram neative oranisms. /ence, it is a differential stain. 2ram stainin involves a four9part process, which includes crystal violet, the primary stain iodine, and the mordant a decolouri"er made of acetone and alcohol safranin, the counterstain. 2ram neative and ram positive oranisms are distinuished from each other !y differences in their cell walls. These differences affect many aspects of the cell, includin the way the cell takes up and retains stains.

2ram9positive !acteria are !acteria that ive a positive result in the 2ram stain test. 2ram9positive !acteria take up the crystal stain used in the test, and then appear to !e purple9 coloured when seen throuh a microscope. This is !ecause the thick peptidolycan layer in the !acterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolouri"ation stae of the test.

2ram9neative !acteria cannot retain the violet stain after the decolouri"ation step: alcohol used in this stae derades the outer mem!rane of ram9neative cells makin the cell wall more porous and incapa!le of retainin the crystal violet stain. Their peptidolycan layer is much thinner and sandwiched !etween an inner cell mem!rane and a !acterial outer mem!rane, causin them to take up the counterstain safranin and appear pink.

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#. icroscope 1. 2lass slides ;. Cover slips 8. Scalpel=Ra"or !lade >. Twee"ers ?. Specimen samples Animal cell • •

Chicken Fish

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#. Bunsen !urner 1. icroscope ;. 2lass slide 8. Cover slips >. Twee"ers ?. 5ater !ottle @. Crystal violet solution > dye contentD E. ethylene !lue solution $ dye contentD . (odine solution #$. 2ram decolouri"er solution ##. 2ram safranin solution #1. S. cerevisae #;. E.coli