A cell is the smallest unit of living matter. All living things such as humans, animals and plants are made up of cells. Organelles are specialised compartments within cells that allow the cells to function properly. These organelles are so small that, until 1938 and the invention of the electron microscope, it was not possible to properly study their structure. There are a variety of different organelles and each organelle performs a different task within the cell. Thankfully there are a few ways to identify which organelle you are looking at under the microscope.
Learn the different cell organelles. Mitochondria, lysosomes, chloroplasts, the Golgi apparatus, endoplasmic reticulum, vacuoles and peroxisomes are all organelles found in eukaryotic cells.
Determine which organelles are features of which cells. For example, vacuoles and chloroplasts are features of plant cells, and lysosomes are features of animal cells. So if you know what type of cell you are looking at, you will be able to find the organelle faster.
Learn the different functions of cell organelles. For example, the organelle that gives a plant its structure is the cell wall. So if you are looking at a cell with a cell wall then you know you are looking at a plant cell.
Memorise the different shapes of cell organelles. Each organelle looks different under the microscope, so this will be your biggest identifier. Mitochondria, for example, are kidney bean shaped with two membranes; chloroplasts have stacks of disks called thylakoids inside them; and endoplasmic reticulum is a long membrane-enclosed structure that resembles a series of folds. Learning what each organelle looks like will help you quickly identify it.