Exploring Ribosomes in Living Cells: A Fresh Look

Ribosomes are cellular factories that churn out proteins. But how do we study these crucial components in living human cells? Here's where time-resolved microscopy comes in. We found that a special dye, YO-PRO-1, interacts with RNA in ribosomes. It's like a tiny detective that helps us see the ribosomes clearly. Using a technique called fluorescence correlation spectroscopy (FCS), we measured how fast these ribosomes move around in cells. The 60S ribosomes, the larger part, move about twice in a second.To measure the size of these ribosomes, we used a clever model that takes into account the cell's stickiness. We figured out that these 60S ribosomes are about 15 nanometers wide, which is tiny but important! We also showed how using this method can help us understand how ribosome numbers change. For instance, in HeLa cells treated with rapamycin, we saw how the ribosome population shifted. This method is a game-changer for seeing what ribosomes do in real time, right inside living cells.