Serial Dilution and Plate Counts

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This video demonstrates how to quantitate bacteria using the serial dilution and plate count method. Bacteria are serially diluted and plated onto petri plates using aseptic technique. This activity is included in the laboratory textbook Biotechnology: A Laboratory Skills Course.
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[@LSI_MGA]

can you add a video that explains what do you do afterwards? how to analyze the plates?

[@IdontCareDontReply]

You count the colonies that form in the plate, that is why it is called plate count. With the colonies found on the plate you calculate the CFU (colony forming unit) and have an estimate of viable cells available per mL from your original sample.

[@IsabelRodriguez-nv2ue]

Thank you so much for this video. It is very clear and easy to follow and understand.

[@memorya1972]

now i know what will i do to my bacteria. thanks for the info :) very well explained.

[@leonardomelo4673]

They really like the color green.

[@Allysiaj2085]

Ghtvgbbt

[@Paganforge]

Right down to the roof of the R&D complex in Hercules, CA.
www.google.ca/maps/@38.0255571,-122.2766188,3a,75y,323.16h,87.15t/data=!3m7!1e1!3m5!1sZ7M37LTwRXIynelM8B9yag!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DZ7M37LTwRXIynelM8B9yag%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D70.26178%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192?hl=en

[@sleeplessbird]

Nice explanation, thanks for the video.

[@bukolajoshua8054]

thanks for the explanation

[@ahmadtalsaadi]

Dear Bio Rad
Thank you for this videos, is it possible to upload let say part 2 video to this one showing who to count the plates after incubation? However some people describe below who to count the plate, I do appreciated, but it will be more complete to add plate colonies counts video to this one!
many thanx to all

[@miraedo92]

thanks for making & uploading such a good video.It's really help in understanding of rDNA Technology subject. I'm having an exam soon.

[@oparaeberechi980]

Thank you for uploading the video is quite educative.

[@vetaya4783]

Very informative , Thank you

[@sclair10]

thank you, I need a refresher and your videos have helped enormously.

[@biannekaulf9221]

Sameeeee.

[@TayyabAli-xm2oi]

Well explained!

[@WorthlessWinner]

You count the number of colonies that grow there; that gives an estimation of the number of bacteria in the volume of liquid you inoculated the plate with.
To get the number of bacteria in 1 ml, you need to account for the volume you put on the plate and the dilution. If you put 0.1 ml on the plate, you need to times that by 10 to get it in ml. If you were counting 10^-5 dilution, you need to times it by 10^5 to get it in 10^1. Cancel those out and you have Colony forming units / ml.

[@aanagul8787]

thank you

[@lorenaviernes6269]

hello! this video is very usefull..:) and it helps me so much for my upcoming research. can i ask.. what can i substitute to lb agar?

[@sharonlizreji3090]

Phosphate buffer

[@ItsSunnySara]

how long should u wait for cooling down?

[@innestri807]

Nice video 👍🏻

[@thesensiblecoderguy]

very well explained

[@thangatamil3265]

kumarsarvam singh

[@codyellsworth7927]

Totally rad-ical

[@user-wk2gp3tu8h]

Thank you sir

[@a.s9509]

Do you discard 100 microliters from the last (7th) microtube?

[@joelarnaud6023]

This way of dilutions are not supposed to be 10 minus 1, 10 minus 2, 10 minus 3 etc?

[@ssaha7776]

They are -1 -2- 3

[@Hira_Hyuna]

Subtitle please.

[@omarito1991]

more of this videos on youtube and less justin bieber videos please :) thanks

[@NileshRoamingNITIAN]

When you love greenery more than anyone !!

[@VLogKeluargaArsyla]

Alhamdulillah hadir

[@JYOtiRaNJanMANgaRaj]

❤❤❤❤❤❤

[@mohitmahajan4021]

there is no plaque counting in this video

[@mohitmahajan4021]

ok

[@user-ts7dz9qs5b]

This isn't plaque assay for phage quantification

[@emmylouhaught8572]

It didn't say how the colonies are counted

[@TrouzzzerSnake]

why call it a plate count when you don't count the plates?

[@you-dont-know-me]

Where can i buy these wicked neon green gloves??

[@ahmadtalsaadi]

Sorry: how NOT who

[@rummanshafi6175]

Then u didn't tell how to count the colonies

[@BioRadEducation]

Hi, Sana! To count colonies, we recommend placing the plate lid-side down (so the agar is up and you're looking at agar underside) on a background that gives you good contrast between the agar and the colonies - for white colonies, a black background works well. Using a felt-tipped pen, dot each colony as you count; by dotting you'll know if you already counted a colony. If the plate has a lot of colonies, use the marker to draw lines on the backside of the plate to mark four equally-sized quadrants, count the colonies in one of the quadrants, and multiply by four for an estimated number of colonies on the plate.