8 Tips for Pouring Perfect Agar Plates Every Time
- 1. Use a Recipe Make up the medium according to the recipe, then add the desired amount of agar powder (normally about 1% w/v) and stir. ...
- 2. Autoclave Autoclave your medium for 25 minutes. ...
- 3. Cool It! Cool the medium-agar mix to 55°C. ...
- 4. Supplement It ...
- 5. Pour the Plates ...
- 6. Let It Set ...
- 7. Get Dry ...
- 8. Use It or Store It ...
How do you make agar plates?
To make 20 agar plates you are going to need:
- a pressure cooker that can reach 15 psi
- an Erlenmeyer flask or glass bottle that can hold at least 750ml of liquid.
- 23 grams of your Malt Extract Agar (MEA) mix
- Sterile Petri dishes
- Parafilm – You can get this here.
- 500 ml of Water.
- Tinfoil
- Scales
- Latex gloves
- Disinfectant solution or alcohol wipes
How do you prepare agar plate?
- Weigh out 28 g of nutrient agar powder using the weighing balance. ...
- Suspend the 28 g of nutrient agar powder in 1 liter (1000 ml) of distilled water in a conical flask.
- Mix the solution by stirring to dissolve the agar.
- Bring the mixture to boil. ...
- Transfer the conical flask containing the boiled/mixed nutrient agar suspension to the autoclave.
How to make sterilized agar plates?
Making Agar Plates
- _1. Choose a recipe. Choose a recipe from the Media Recipes page or use one of your own. ...
- _2. Gather supplies
- _3. Prepare media. Use a glass container (ideally an Erlenmeyer flask) that will hold at least twice the volume of your media.
- _4. Sterilize. Sterilize using one of the methods described on the Sterilizing Liquids page. ...
- _5. Pour into plates. ...
How to make nutrient agar at home?
Pour into plates
- Prepare a suitable work area. ...
- Label the plates with the type of media you will pour into them.
- Swirl the hot media vigorously to mix.
- Cool the media until it is just cool enough to handle, about 20-30 minutes. ...
- Swirl the media again to mix just before pouring; be careful not to incorporate bubbles.
How do you melt and pour agar plates?
0:202:53How to Melt and Pour Agar Plates - YouTubeYouTubeStart of suggested clipEnd of suggested clipI'm using a simple hot pot. Be sure not to preheat your water because if you do the bottle mayMoreI'm using a simple hot pot. Be sure not to preheat your water because if you do the bottle may shatter when you put it in don't use a microwave as this can make a steam bubble in the agar.
How do you pour your own agar?
_5. Pour into platesPrepare a suitable work area. ... Label the plates with the type of media you will pour into them.Swirl the hot media vigorously to mix.Cool the media until it is just cool enough to handle, about 20-30 minutes. ... Swirl the media again to mix just before pouring; be careful not to incorporate bubbles.More items...
How do you pour bacterial plates?
5:368:50Plate Pouring Protocol - YouTubeYouTubeStart of suggested clipEnd of suggested clipTo begin the plate pouring process we light the flame at our gel pouring station and dilute ourMoreTo begin the plate pouring process we light the flame at our gel pouring station and dilute our antibiotic into the 60 degrees Celsius agar mix. We're adding 220 microliters.
How do you pour agar plates without condensation?
Tips for Pouring and Storing Agar Plates• ... • It is best to pour agar that is about 50º C. ... • If you pour your own agar plates and get lots of bubbles, try gently passing the flame of a Bunsen. ... • To prevent condensation of water in plates, let them solidify and dry at room temperature until the. ... •
Why is my agar agar not solidifying?
If there are still grainy bits of agar floating or sticking to the bottom of the pan, the jelly will not set properly. If using powder, mix all the ingredients along with the agar and let it sit for 5 minutes. Never mix agar powder with warm/hot water as it will clump and become impossible to dissolve.
Do agar plates need to be refrigerated?
Store agar plates in a refrigerator. Most bacteria cannot grow well in cold temperatures. Store plates in a cold room if a refrigerator is not available. If you are storing plates in a cold room, check the plates for condensation a few hours after pouring.
What temperature do you pour agar?
Heat in one minute intervals on low power until all of the agar is melted. Between intervals, gently swirl the bottle to make sure the agar is melting evenly. While wearing heat-protective gloves, carefully remove the hot bottle and let it cool to between 75– 55°C before pouring.
Why are agar pours stored in a water bath?
A water bath set at 50°C is useful to store bottles of molten agar to maintain the optimal temperature prior to pouring plates.
How long do agar plates take to dry?
*Pro-Tip* It takes roughly 30 min for our plates to solidify at room temperature, however we leave them out at room temperature overnight to allow them to dry. After overnight drying, we place the plates in a plastic bag with an absorbent material to reduce condensation.
Why are my agar plates wet?
It's probably condensation from the agar warming up and evaporating some of the liquid onto the lid. What I do when the plates are too wet is to lift the lids and leave them open a centimeter or so for half an hour to allow the liquid to evaporate.
Why do you store agar plates upside down?
Petri dishes need to be incubated upside-down to lessen contamination risks from airborne particles landing on them and to prevent the accumulation of water condensation that could disturb or compromise a culture.
How do you dry agar plates faster?
Get Dry. Dry the plates in the laminar flow hood with the lid slightly off for 30 minutes (or in a 37°C incubator for 2–3 hours, or room temperature for 2–3 days). Drying the plate is very important for storing the plates and growing colonies on them.
How do you make agar without a pressure cooker?
ProcedurePrepare your Liquid Culture or Agar to be sterilized.Pour into a Mason Jar.Loosely fit the Mason Jar lid.Bring to a raging boil a pot of water.Submerge the mason jar into the boiler water.Set timer for 20 minutes, and boil (Careful to make sure you have enough water in the pot at all times)More items...•
How do you make agar plates without a pressure cooker?
4:3420:50NO PRESSURE COOKER Agar Prep for Edible Mushroom Projects!YouTubeStart of suggested clipEnd of suggested clipI can make around 30 jars of agar with this nine dollar pre-mixed agar blend keep in mind that youMoreI can make around 30 jars of agar with this nine dollar pre-mixed agar blend keep in mind that you really only need a little less than a half inch of agar. Anything more and it's just a waste of agar.
What temperature should you pour agar?
Water temperature should remain at around 100°C. Leave it in the water bath until the agar is completely melted. While wearing heat- protective gloves, carefully remove the hot bottle and let it cool to between 75–55°C before pouring.
How do you prepare agar media?
How to prepare nutrient agar?Suspend 28g of nutrient agar powder (CM0003B) in 1L of distilled water.Mix and dissolve them completely.Sterilize by autoclaving at 121°C for 15 minutes.Pour the liquid into the petri dish and wait for the medium to solidify.
Non-Autoclaved Plates
Let’s say your autoclave breaks and you need agar plates in a flash. After going from lab to lab, begging for plates and coming up short, you’re still in a bind. Rather than autoclave, you can measure out your desired mass of agar, put it into a dry Erlenmeyer flask, add your water, and microwave it for 2-4 minutes, depending on the volume.
Autoclaved Plates Poured on the Bench Top
Let’s say your laminar flow hood breaks, or is completely full. You’ve already autoclaved your media, it is ready to pour. What do you do? Under these circumstances, you can pour plates on your bench top.
1. Use a Recipe
Make up the medium according to the recipe, then add the desired amount of agar (normally about 1% w/v) and stir. If you autoclave without stirring, with the agarose still floating on top of the liquid, you get an agarose cake in the medium. Interesting, but useless.
2. Autoclave
Autoclave your medium for 25 minutes. After autoclaving, you can of course store the medium-agar mix in a toughened glass bottle then melt it in a microwave or water bath when needed. Make sure you use toughened glass bottles, or disaster (see #2) can strike.
3. Cool It!
Cool the medium-agar mix to 55°C. For routinely consistent results, do the cooling for a couple of hours in a 55°C water bath. Agar starts to solidify at about 50°C. Using the water bath means you can consistently cool the mixture to just above the solidification temperature.
4. Supplement It
You can now add any antibiotics or supplements, and be confident that the agar is at a suitable temperature because you have cooled it in the water bath.
5. Pour the Plates
Use about 30 mL of the agar-medium mix for each plate when using a 100 mm diameter plate. The less agar-medium mix in each plate, the more easily they will dry out. 30 mL is a good amount for long-term storage, 10–20 mL is fine if you are going to use the plates relatively soon.
6. Let It Set
If there are any bubbles in the plates, briefly pass the flame over to pop them. Classic error: trying to move the plates before they’ve set is just asking for trouble. Just leave them alone (and maybe admire your perfect agar plates while you wait)!
7. Get Dry
Dry the plates in the laminar flow hood with the lid slightly off for 30 minutes (or in a 37°C incubator for 2–3 hours, or room temperature for 2–3 days). Drying the plate is very important for storing the plates and growing colonies on them.
Uses
The pour plate technique can be used to determine the number of microbes/mL in a specimen. It has the advantage of not requiring previously prepared plates, and is often used to assay bacterial contamination of food stuffs.
Procedure of Pour plate technique
Prepare the dilution of the test sample expected to contain between 30-300 CFU/mL. (Follow serial dilution technique)
Results
After 24-48 hours, count all the colonies ( again: note that the embedded colonies will be much smaller than those which happen to form on the surface). A magnifying colony counter can aid in counting small embedded colonies.
Disadvantages of Pour plate method
Preparation for the pour plate method is time-consuming compared with the streak plate/and or spread plate technique.
Tips
Buy bouillon that doesn't contain preservatives or flavorings. These can make it harder for your medium to grow and it might be harder to see growth if your bouillon has specks of seasonings. Thanks! Helpful 0 Not Helpful 0
About This Article
This article was co-authored by wikiHow staff writer, Jessica Gibson. Jessica Gibson is a Writer and Editor who's been with wikiHow since 2014. After completing a year of art studies at the Emily Carr University in Vancouver, she graduated from Columbia College with a BA in History.
