Cell biology &genetics - lab report Essay Example | Topics and Well Written Essays - 750 words

Cell biology &genetics - lab report - Essay Example The objective of this experiment is to observe the several stages of mitosis in an onion root cell through a light microscope. Onion root tips were prepared by washing in clean water then rinsing with distilled water. After this, a root tip section about 2mm in thickness was cut from the root tip using a sterilized scalpel; this was then placed on a glass slide with a drop of distilled water on it to avoid dehydration. Afterwards the root tip section was them fixed in Carnoy’s fluid inside a Bijou bottle for about 10 minutes. After fixing, the section was then transferred to a Petri dish containing distilled water where it was rinsed for approximately 2 minutes. After rinsing, the root tip section was then placed inside a bijou bottle containing 1 ml of 1M HCl and incubated at about 60ï‚ °C for about 5 minutes. The contents of the tube were then poured into a Petri dish and the root tip carefully picked out using forceps and transferred into another Bijou bottle containing aceto-orcein which was then left in a dark chamber for about 10 minutes. The bottle was then removed from the chamber and the root tip carefully removed using forceps and placed on a slide on which a drop of 45% acetic acid had been placed, this was then covered with a cover slip. By this time the root tip section was already well softened and stained; the tip was then squashed by slightly tapping on the cover slip with a pencil until it was evenly spread out under the cover slip as a pink mass. The glass slide with the root tip ready for observation on the microscope was then transferred to a light microscope and viewed at x400 magnification strength. Photographs of the cells undergoing mitosis were then taken and drawings made of the various stages of mitosis. It was observed in the experiment that the cell division process assumed all the four stages shown in the images above and that the staining clearly revealed the features of all the four stages it takes for a cell