It is important to use a needle rather than an inoculating loop because the needleis used to transfer the specimen to the soft agar medium. The inoculating loop isused to transfer specimens in a liquid medium or plating. Using the needle willcreate more growth to occur along the stab line. Beside this, why should you use an inoculating needle when making smears?
Solid media is more dense over a smaller area so an inoculating needle is used to retrieve the specimen so not too much is transferred, while a liquid medium features a more spread out specimen so the inoculating loop can collect more liquid and enough specimen to observe.
Subsequently, question is, what is the function of inoculating loop? Inoculation loop. An inoculation loop, also called a smear loop, inoculation wand or microstreaker, is a simple tool used mainly by microbiologists to pick up and transfer a small sample (inoculum) from a culture of microorganisms, e.g. for streaking on a culture plate.
Correspondingly, why can't the inoculating loop be used for stab inoculation?
The tube was inoculated with the needle instead of a loop because the stab needle goes into the solid serratia. When using a loop needle you need to swirl it, which could make it difficult to transfer all the bacteria into a solid culture.
How can some anaerobes be maintained in pure cultures?
The anaerobes will grow deep within the agar in the anaerobic environment it provides. After suitable growth, the stab may be refrigerated. Anaerobes can also be maintained in thioglycollate broth or cooked meat medium.
Related Question Answers
When would you use a negative stain?
Negative stain is used when viewing bacteria by wet mount or hanging drop slide to view bacterial motility. Negative staining is used when it is important to be able to view the bacteria without using harsh stains or performing the heat fixing technique that could possibly distort or change the shape of the bacteria. What is the inoculating loop used for?
Inoculation loop. An inoculation loop, also called a smear loop, inoculation wand or microstreaker, is a simple tool used mainly by microbiologists to pick up and transfer a small sample (inoculum) from a culture of microorganisms, e.g. for streaking on a culture plate. What is the difference between a simple and differential stain?
A simple stain will generally make all of the organisms in a sample appear to be the same color, even if the sample contains more than one type of organism. In contrast, differential staining distinguishes organisms based on their interactions with multiple stains. Why is time an important factor in simple staining?
Why is time an important factor in simple staining? Time is important because it creates a contrast between the bacteria and the stain. If you over or under stain you won't be able to see bacteria. A properly prepared bacterial smear would mean the bacteria are evenly spread out and properly fixed. Why are inoculating loops flamed?
The purpose of flaming an inoculating loop is to prevent or reduce the chances of cross-contamination of the cultures being inoculated. It is required to sterilize the inoculating loop or needle by passing it an angle through the flame of a Bunsen burner until the whole length has turned into bright orange or red Why must loops be cooled first?
The inoculating loop must be cooled before it touches the surface of the medium. The loop must be cooled to prevent killing the bacteria. If the loop is too hot, it will kill the bacteria and sizzle and melt the media that further promotes contamination. How do you sterilize an inoculating loop?
Sterilize your wire inoculating loop by passing it at an angle through the flame of a Bunsen burner until the entire length of the wire becomes glowing red/orange from the heat. Important: Never lay the loop down once it is sterilized or it may become re-contaminated. Why is a single stab with an inoculating needle used to inoculate SIM medium?
Uses. Inoculation needles are primarily applied in microbiology for studying bacteria and fungi on semi-solid media. Stab cultures specifically require the inoculation needle and is used to study cell motility, microbial oxygen requirements using Thioglycolate cultures, and the gelatin liquefaction of bacteria. What is a stab culture used for in microbiology?
Stab cultures are similar to agar plates, but are formed by solid agar in a test tube. Bacteria is introduced via an inoculation needle or a pipette tip being stabbed into the center of the agar. Stab cultures are most commonly used for short-term storage or shipment of cultures. What is the importance of flaming the inoculating loop or needle before and after each inoculation?
The flaming process prior to the inoculation is important to prevent contamination of the cultures being inoculated. The flaming process after each inoculation is important to prevent the contamination of further inoculations for which the inoculation instrument will be used. Why should you never Label the lid of an agar plate?
Why should you never label the lid of an agar plate? The plate bottom is labeled because it cannot be separated from the medium. Labeling the lid of the agar plate can be troublesome because it can be separated from the medium, therefore the top can accidentally be interchanged. How long does it take to sterilize an inoculating loop or needle?
24-48 hours
What are the different types of inoculating loops and needles?
Inoculating Loops & Needles … inoculating loops and needles are made from high quality polypropylene and are available in 3 styles; needle, 1µl loop and 10µl loop. The stems are flexible and can be bent to access small volume tubes and dishes and they are color-coded for easy identification. What is the purpose of flaming an inoculating loop?
An inoculation loop is simple laboratory equipment mainly used by mycologists to transfer microorganisms to a growth media. The purpose of flaming an inoculating loop is to prevent or reduce the chances of cross-contamination of the cultures being inoculated. Why is a straight inoculating needle used?
Prevents bacteria on the neck from entering or spreading through the neck of the culture. What is a straight needle used for? a straight needle is used to inoculate an agar deep tube so the inoculum can be drawn out from the bottom of the tube in a straight line, along the line of insertion. What are inoculating loops made of?
Inoculating loop. A tool usually made of platinum or nichrome wire in which the tip forms a small loop with a diameter of about 5 mm, and is used to smear, streak, or take an inoculum from, a culture of microorganisms. Why is it essential that the wire loop be clean?
Before every flame test, it is necessary for the wire loop to be clean so that the test will give accurate results. Without cleaning the wire, the test would not give perfect results. Why do we heat Nichrome loop before use?
Microbiologists use inoculating loops to transfer microorganisms to growth media. It is easy to sterilize and reuse because nichrome wire resists deterioration with repeated heat/cooling cycles. When cooled, it is ready for culture inoculations. In another application, use this loop to perform a flame test. What is platinum loop?
Platinum loops and needles are used for transferring bacterial cultlres. These loops and needles are made of B&S platinum wire with 15% iridium added for rigidity, permitting a thinner wire for delicate work. Loops are fused to form a "perfect circle" with an inside tolerance of +/-0.02 mm to ensure accurate delivery. How can a streak plate become contaminated?
How can a streak plate become contaminated? By letting too much air in returning loop. by no using proper aseptic technique and leaving the lid off the plate too long. What is the purpose of Subculturing?
Subculturing prolongs the lifespan of the cells or microorganisms, allowing for long-term maintenance and observation of the culture. The process of subculturing involves transferring microbes from one growth container to another, providing the microbes with a fresh supply of nutrients on a solid or liquid medium. What is the purpose of flaming?
The purpose of flaming is not to sterilize but to warm the opening of the bottle and create air convection currents up and away from the opening (i.e., updraft). The warm, rising air helps prevent dust particles and other contaminants from entering the bottle. Why is it important not to contaminate a pure culture?
It is important not to contaminate a pure culture because the bacteria present will be mixed with other bacteria's. The purpose of the pure culture is to have one type of bacteria to be added to another medium. This can give you completely different results. How do the pure broth cultures differ?
How do the pure broth cultures differ? Broth cultures are in a liquid phase because they lack agar and slant cultures are a solid medium that occupies a test tube at an angle to allow a large surface area for growth. Why are culture media sterilized before use?
When microbiological media has been made, it still has to be sterilized because of microbial contamination from air, glassware, hands, etc. Within a few hours there will be thousands of bacteria reproducing in the media so it has to be sterilized quickly before the microbes start using the nutrients up. What is the function of sterile mineral oil in the maintenance of stock cultures?
The presence of sterile oil maintains the moisture in agar, reduces organism's metabolism to the lowest extent (saving energy), and gives dissolved oxygen thus providing a viable environment for the maintenance of the culture for longer period (about 10-15 yrs). What is the purpose of flaming when using aseptic technique?
The purpose of flaming is not to sterilize but to warm the opening of the bottle and create air convection currents up and away from the opening (i.e., updraft). The warm, rising air helps prevent dust particles and other contaminants from entering the bottle. What are some signs of growth in a solid medium?
What are the signs of growth on a solid medium? The appearance of a visible coating or colonies on the surface of the medium. What are some signs of growth in a liquid medium? Turbidity, pellicle, sediment, layer or puff balls just below surface. 
