Preparing microscope slides and cell fractionation Flashcards
What is step 1 of preparing a microscope slide
Use a pipette to put a small drop of water on the centre of the slide
What is step 2 of preparing a microscope slide
Use tweezers to place a thin section of your specimen on top of the water drop.
What is step 3 of preparing a microscope slide
add a drop of a stain. Stains are used to highlight objects in a cell.
What is step 4 of preparing a microscope slide
Add the cover slip. Make sure to carefully lower it avoiding air bubbles.
What are artefacts?
Objects you can see down the microscope that aren’t part of the cell/specimen your viewing.
What is cell fractionation
Separating organelles from it’s cell
What is step 1 of cell fractionation
Homogenisation - breaking up the cells. Vibrating or grinding up cells in a blender. Breaks plasma membrane releasing organelles into a solution.
How must the solution of organelles be kept during cell fractionation
Ice cold - reduce enzyme activity, same water potential in and out of cells reduces osmotic effect and add buffered pH so pH doesn’t fluctuate as could change shape of cell.
What is step 2 of cell fractionation
Filtration - Pass the solution through a gauze to separate large cell debris or tissue debris.
What is step 3 of cell fractionation
Ultracentrifugation - Pour mixture of organelles into test tube. Place tube in a centrifuge and spin at a low speed. Heaviest organelles will fall to bottom. Repeat, with increasing speed, until all organelles are separated
What is the heavy material that sinks to the bottom of the test tube in ultracentrifugation called
The pellet
list these organelles heaviest to lightest - ER, nuclei, mitochondria, chloroplasts, lysosomes, ribosomes
Nuclei, chloroplast, mitochondria, lysosomes, ER, ribosomes
What is the suspended material above the pellet in the test tube in ultracentrifugation called
The supernatant
