how to videos stain mouth smears video microbiology course

by Saige Yost 7 min read

What is a bacterial smear and simple stain?

Microbiology - 003 - Bacterial Smear and Simple Stain. Transcript or Alternate URL: Because bacteria are, for the most part, transparent, we use stains to give them color for microscopic observation. Making a bacterial smear prepares the bacteria to be stained and is the first step of most staining procedures.

How do you stain a bacterial culture in microbiology?

Get a clean slide. If you’re staining bacteria from a broth culture, transfer a loopful of the broth directly to the slide. Otherwise, add a drop of water to a sterilized loop and place it on the slide, then sterilize the loop again. Transfer a very small amount of bacteria from a colony on a plate to the drop of water and mix.

What is a bacterial smear and why is it used?

Because bacteria are, for the most part, transparent, we use stains to give them color for microscopic observation. Making a bacterial smear prepares the bacteria to be stained and is the first step of most staining procedures.

How do you stain a bacterial smear with crystal violet?

Take your prepared bacterial smear and use a staining bridge to suspend it above a staining trough or sink. Use a dropper to cover the smear completely with stain – in this example, we’re using crystal violet. Allow the stain to sit for 60 seconds, then rinse the slide with water to remove excess stain.

How do you prepare a smear for staining?

1:302:58Preparation of a bacterial smear for staining - YouTubeYouTubeStart of suggested clipEnd of suggested clipSet down the slide and allow the smear to air-dry. Once completely dry heat fix the smear byMoreSet down the slide and allow the smear to air-dry. Once completely dry heat fix the smear by carefully passing the slide smear facing upwards through the Bunsen flame three.

What are the steps in the smear technique?

Smear from PlateLabel your slide. ... Pick a well-isolated colony.Prick it with your sterile needle, or slightly scoop the edge of the colony with your sterile loop.Place your needle/loop in the center of the drop and with a spiraling circular motion spread the bacteria on the slide.Set the slide aside to air dry.

What are the steps of bacterial smearing?

SMEAR PREPARATIONPlace one needle of solid bacterial growth or two loops. of liquid bacterial growth in the center of a clean slide.If working from a solid medium, add one drop (and only one drop) ... Now, with your inoculating loop, mix the specimen with the water. ... Place the slide on a slide warmer and wait for it to dry.

What is stained smear in microbiology?

A bacterial smear is simply that—a small amount of culture spread in a very thin film on the surface of the slide. To prevent the bacteria from washing away during the staining steps, the smear may be chemically or physically “fixed” to the surface of the slide.

How do stains work in microbiology?

In preparation for staining, a small sample of microorganisms is placed on a slide and permitted to air dry. The smear is heat fixed by quickly passing it over a flame. Heat fixing kills the organisms, makes them adhere to the slide, and permits them to accept the stain.

What are the two types of smear preparation?

Four different types of smear preparation methods (conventional method, blood film method, drop and rest method, and water-wash method) were carried out according to the standard reference as described below.

What are staining techniques?

Staining is a technique used in microscopy to enhance contrast in a microscopic image. Stains and dyes are frequently used to highlight structures in microbes for viewing, often with the aid of different microscopes.

How do you stain bacteria?

2:064:19Applying a Simple Stain to a Bacterial Culture - YouTubeYouTubeStart of suggested clipEnd of suggested clipBe sure to fill the entire circle with the dye. Leave the stain on for 30 seconds gently wash theMoreBe sure to fill the entire circle with the dye. Leave the stain on for 30 seconds gently wash the slide with distilled. Water drain off any excess.

What is simple staining in microbiology?

Simple staining involves directly staining the bacterial cell with a positively charged dye in order to see bacterial detail, in contrast to negative staining where the bacteria remain unstained against a dark background.

What are the 4 steps of gram staining?

The performance of the Gram Stain on any sample requires 4 basic steps that include applying a primary stain (crystal violet) to a heat-fixed smear, followed by the addition of a mordant (Gram's Iodine), rapid decolorization with alcohol, acetone, or a mixture of alcohol and acetone and lastly, counterstaining with ...

Why do we stain smears?

The purpose of staining is to increase the contrast between the organisms and the background so that they are more readily seen in the light microscope.

What is staining and types of staining?

Simple StainingCharacteristicsDirect stainingIndirect stainingStain usedBasic stainAcidic stainCharge of stainPositiveNegativeExamplesMethylene blue, crystal violet, carbol fuschinNigrosine, india ink, congo redOutcomeStains the specimenStains the background2 more rows

What is a bacterial smear?

Making a bacterial smear prepares the bacteria to be stained and is the first step of most staining procedures. A successful smear will have a single layer of bacteria fixed to the slide, ready to be stained and then observed under a microscope. Get a clean slide.

What is 003 microbiology?

Microbiology - 003 - Bacterial Smear and Simple Stain. This opens in a new window. Because bacteria are, for the most part, transparent, we use stains to give them color for microscopic observation. Making a bacterial smear prepares the bacteria to be stained and is the first step of most staining procedures.

Why do we use stains?

Because bacteria are, for the most part, transparent, we use stains to give them color for microscopic observation. Making a bacterial smear prepares the bacteria to be stained and a simple stain is a quick and easy way to observe bacteria.

How to stain a broth culture?

If you’re staining bacteria from a broth culture, transfer a loopful of the broth directly to the slide. Otherwise, add a drop of water to a sterilized loop and place it on the slide, then sterilize the loop again. Transfer a very small amount of bacteria from a colony on a plate to the drop of water and mix.

How to remove a stain from a slide?

Allow the stain to sit for 60 seconds , then rinse the slide with water to remove excess stain. Get a piece of bibulous paper and gently blot the slide. Don’t wipe – this will disturb the bacteria. The slide is now ready to be viewed under a microscope.

How to get bacteria on a slide?

Transfer a very small amount of bacteria from a colony on a plate to the drop of water and mix. Spread the water-bacteria mix around to about the size of a dime. Air dry the slide, allowing the water to evaporate. This will deposit the bacteria on the slide’s surface.

What is a Gram stain?

The Gram stain is a fundamental tool used to differentiate bacteria by placing them into one of two general groups. Bacteria that are a deep purple after staining are called Gram + (positive), while bacteria that appear a lighter pink are called Gram - (negative.)

What is the process of breaking down blood cells?

Some bacteria are able to break down blood cells by a process called hemolysis. Knowing what type of hemolysis a bacterial strain is capable of can be helpful in identifying several types of bacteria, especially organisms isolated from human tissue such as Streptococcus and Staphylococcus species.

Why do we use stains to color bacteria?

A serial dilution is a series of successive, measured dilutions in order to obtain a known, workable concentration of bacteria. Because bacteria are, for the most part, transparent, we use stains to give them color for microscopic observation .