In this video, we're going to talk about some other types of staining, specifically special staining. And so special staining, as its name implies, is going to use really special procedures to stain very specific structures, either on the inside or on the outside of cells. Now examples of special stains include the capsule stain, endospore stains, and flagella stains. And so if we take a look at our example down below, we can see today's special, special staining, which is going to be used to stain very specific cell structures. And so on the far left, we're showing you the example of the capsule stain, which is going to be staining the capsule of bacteria. And so here we're showing you the bacteria of the human eye, their capsules being stained here in white. So you can see that, you're able to actually visualize the capsules, this barrier that surrounds the cell, as these white borders, because of the particular stain that's being used here. Now, next what we're showing you here is the endospore stain. And the endospore stain, as its name implies, allows for the visualization of endospores. And so here in this image, we're staining the endospores of the bacteria Bacillus cereus. And the endospores are showing up as this bluish-greenish color. So all of these little blue dots that you see represent the endospores being formed by this particular bacteria. Now last but not least over here on the far right, we're showing you another example of a special stain called the flagella stain, which as its name implies allows for the visualization of flagella. And so here it's showing you the flagella of the same bacterium, Bacillus cereus. And so you can see all of the flagella branching off of this bacteria. Now notice over here on the left hand side, it's also showing you the same bacteria. Bacillus cereus is being shown in the left, the middle, and the right image. But notice that none of the flagella are actually being visualized over here on the left-hand side, but that is because the flagella stain is not being used over here. But as soon as the flagella stain is used, notice that where the scientists are able to visualize the flagella. And so this shows you the importance of using these special stains to be able to visualize the specific structures of interest a lot more easily. And so this here concludes our brief lesson on special staining and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.
Other Types of Staining - Video Tutorials & Practice Problems
Special Staining
Video transcript
Which of these is considered a special stain that correctly matches its description?
What is the major difference between special staining techniques and differential staining techniques?
Fluorescent Dyes
Video transcript
This video, we're going to talk a little bit more about fluorescent dyes. Recall from our previous lesson videos that fluorochrome dyes and immunofluorescence can be used to observe cells and or cell components. Recall that immunofluorescence is a very specific technique that combines a fluorochrome or a fluorescent dye with an antibody protein. This will allow for the tagging of very specific objects and very specific molecules. It's also worth noting that some fluorescent dyes can actually be changed by cellular processes. Therefore, some fluorescent dyes can be used to distinguish between living cells that contain those cellular processes and dead cells. Distinguish the living from the dead cells that the dead cells do not contain those cellular processes. If we take a look at our image down below, what we're showing you is an image of immunofluorescence, which is going to use a fluorochrome combined with an antibody. Over here on the far left, what we're showing you is the fluorochrome, which is in red. These red circles are these fluorochrome molecules or these fluorescent dyes that will fluoresce. In the bottom in green, we're showing you the antibodies, which are these Y-shaped proteins. These Y-shaped protein antibodies are capable of binding to very specific antigens. Antigens are going to be molecules that antibodies bind to. Over here, you can see that the antibodies and fluorochromes are combined together to create a single molecule. Over here, what we have is a string of bacteria, that all contain these antigens, these very specific antigens. The antibody, this Y-shaped protein, is going to be specific to binding to the antigen. The fluorochrome is only going to fluoresce when the antibody actually does bind to the antigen. If we take a look at this image over here on the right, notice that all of the Y-shaped antibodies are binding to the antigen on the surface of the bacteria. At that point, each of these fluorochromes is going to fluoresce, and that fluorescence can be detected. Ultimately, this is what we're seeing here in this image, is the fluorescence due to immunofluorescence, the use of the antibody here. This here concludes our brief introduction to fluorescent dyes and immunofluorescence. Once again, we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.
_______ is/are used to attach fluorochrome molecules to antigens on the surface of bacterial cells in immunofluorescence.