Serial Dilutions of a Bacterial Culture

[@glendasworld4125]

You explained WAY WAY better than my professor. Thank you! I understand all of it now!

[@glendasworld4125]

By the way, I’m answering questions like this for my hw. One of the questions is “stefanie and Bradley are lab partners. Using a 10^-2 dilution, Stefanie counts 57 cells in a Petroff-Hauser chamber. Bradley counts 63 cells using the same dilution. What was the average number of cells per mL in the original sample? assuming 25 squares and standard volume.” So I already know how to do answer this kind of question thanks to your video. But I’m not sure how many mL of the dilution they put on the plate or what they mean by “standard volume.” Could you help me with this? It’s for my microbiology class.

[@mrpeanutbutter6094]

Maybes it your prof

[@sam.9602]

Yes he did! My professor tried teaching us without using any units. Talk about confusing :(

[@suya4825]

The best explanation I've found so far on KZbin. Than you very much!

[@infinitecouture13]

I had no idea what my text book was talking about when it came to this topic, but the way you explained it is so simple & easy to comprehend! Thank you so much for making this vid!

[@amailyakter6589]

the best explanation I have ever found!!!! today all sorted about CFU!! May Allah bless you, Mr. lecturer!!! you are the best.

[@mohsenakhavan3500]

Fantastic explanations. I recommend this video to every microbiology students who wants to answer the questions about CFU in the exam. He clearly describe the subject. I couldn't find a word in the literature to thank you.

[@refresheronce5902]

This is really helpful and makes concept clear on serial dilution. Thank you so much.

[@krystaljames6710]

You are an awesome teacher! We really do appreciate you! Keep doing what you do, one day you will be rewarded for it.

[@MrCompenso]

Very clear and helpful! I'm preparing for an internship in biotech and your videos are making me feel much less nervous about going into a new field. Thank you!

[@ProfGillesBolduc]

That is exciting! The biotech field can be very rewarding . I wish you the best.

[@edwardmaximus5439]

This part in Micro was so confusing to me, thank you so much!

[@DurgeshKumar-pd1qu]

Very Good Explanation. Most clear explanation with good example 👍👍👌nice and thank you sir

[@jeyswam]

Wonderfully explained. I am glad I found this video. Thank you

[@desmondbaptiste861]

Well thought out video; easy to understand, great content, animations were on point and was an added help. Much appreciated.

[@elanawills2364]

This is the best video explaining serial dilutions. Thank you!!!

[@user-zr7gf7jh4c]

강의력이 우리 교수님의 9100만배 인정합니다

[@janniepowerz8893]

He is far better than my lecture, I have understood this very well ,thanks so much

[@ProfGillesBolduc]

It's my pleasure

[@OkohPee]

Man, you are a teacher par excellence. Thank you for the presentation

[@juliahicksfav]

I appreciate the variety of examples. Thank you!!!

[@cocoaxo6126]

Thank GOD for youtube.

[@realtorvalentina]

This has helped me sooo much for my micro test, thank you for taking the time to do this!

[@csm1276]

This is very useful and great explanation with examples.Thanks Gillis Bolduc.

[@alexisalexia6880]

Wow,this is the best explanation.

[@iMusikkForeva]

You’re a great teacher. Thank you so so much!

[@anna.sortini]

THANK YOU!!!! It helped me a lot for my micro lab test.

[@shamekamir]

THANK YOU!!!!!!!!! You just saved my grade!

[@benjaminnketsiah829]

You are the best keep it it up.I understand now

[@sonyablunt4181]

I'm watching to freshen up for a job interview! THANK YOUUUU

[@ProfGillesBolduc]

You well be great. Let me know if you get the job!

[@nnabuikeogbonna5565]

Highly explained. Very useful. Thanks so much

[@taongaphiri6084]

i enjoyed the explanation, its the best I have seen.

[@sevdaqurbanova8339]

Thank you for the best explanation!

[@tictactoj]

Incredible work, +1

[@kristenfarney6786]

This is very helpful, thank you! You are a good teacher!

[@sandisonkosi9835]

I had to subscribe to this what an easy way to make me understand dilutions.

[@Tes-qe1jc]

That was an amazing and crystal clear explanation of serial dilution of a bacterial culture video on KZbin! Please upload other videos on how to treat #organic #wastes using #Actinomycesbacteria.

[@kundananjinawanzi9561]

Its so so helpful, thank you

[@husnabassal7686]

This video is amazing!! Saved me a lot og time and confusion. Thank you!

[@beverleyp.3727]

The best explanation that I've seen yet! Thank you :-)

[@ProfGillesBolduc]

Beverley P. , that’s awesome. Thank you!

[@samritisharma7683]

It is very nicely explained. Thank you.

[@janniepowerz8893]

Omg,this is so good ,this man can really explain,I have liked this ,feel so good ,thank indeed,great work ,

[@aloodenishthescientist1]

Very detailed information clearly explained. Thank you.

[@Beonrightside]

thank you very much . it was very helpful

[@thilinijayasinghe3653]

This is great. Thank you million times.

[@bettylou1030]

excellent explanation, thanks for sharing!

[@sarifm5688]

You are a life saver sir!

[@shashidharnrao]

excellent presentation. very clear.

[@maksudkerluku7517]

Awesome explanation...thank you, sir !!!

[@hybridone890]

Amazing, best I've found!

[@juanitacruz5237]

Best explanation. Thank you

[@priscilaesthertalavera2987]

Thank you so much! Perfectly explained

[@nvkn2680]

Awesome explanation! Thank you so much!

[@pritichristian2673]

Thanks. Very useful..

[@naleisasashaderoche295]

This was helpful! Great Video !

[@mahdiah5518]

so so helpful, wish I had found this before sitting my A levels

[@priyambadanag6708]

Best explanation ever👍

[@amjadzubair8421]

Smooth simple great educational

[@Nik-ps9so]

you are a blessing truly!

[@kalifasanneh9051]

Thank you very much. Very education . Well explained.

[@princeaju2418]

Thanks for the explanation 👍🏻👍🏻

[@hitkarshkushwaha2434]

Love your lecture!!

[@kumaylhassan]

There is NO video that explain CFU/ml into LogCFU/ml.. Can AnyBody tell me how to calculate it ?

[@jahmanwritingco2108]

Very simplified...Thank you.

[@napats.8743]

it is so clear. Thank you so much !!

[@fuugawa741]

Thank you so much, savior!!

[@jenniferwarren8643]

This was super helpful. Thank you!

[@firatyildirim2288]

Simple and informative, thank you very much.

[@hafizibrahim9501]

Thank you!!!

[@originalMP3com247]

This is such a great tutorial

[@HK-mq6ys]

Thank you so much, this was very herpful👌

[@pranishsawant9932]

very neatly explained and presented. nice job, but please refrain from saying millilitres as 'mils' rather than as 'ml'. that is all.

[@alejandralarasosa7187]

Thank you! I understand it now !

[@mahartanvir2653]

best teacher

[@mduplooy6763]

brilliant! THANK YOU.

[@iana6659]

Amazing explanation !! I just have one enquiry Why would we have errors if we chose a plate with less than 30 bacterial colonies ?

[@ProfGillesBolduc]

There’s an increase of error because we’re dealing with small numbers. If you have a plate with 10 colonies and a second one with 20 colonies, this isn’t big a difference until you start multiplying and the small error now becomes multiplied.

[@iana6659]

What type of error are you referring to when you mentioned the small error ? I mean error due to what ?

[@ProfGillesBolduc]

It’s all mathematical. There’s less of a difference between 250 CFU and 275 CFU than if your talking about the difference between 5 and 30 CFU. If you count either 250 or 275CFU from a sample diluted 10^6 times than your answer is either 2.5 x10^8 CFU or 2.75 x 10^8 CFU. But if you use data values such as 5 or 30 CFU from a sample that’s similarly diluted 10^6 than your calculated answers would be either 5 x 10^6 or 3 x 10^7 which are more different. Thus there’s a bigger error between to two answers. To make your data more accurate you would average data from triplicate plates with CFU between 30 and 300. This is pretty much standard in most labs. I sometimes hear that scientist will use plates with CFU counts between 20 and 200.

[@silverdream26]

Thank you so much. Great explanation.

[@Michelle-yg2vn]

Very helpful!

[@kelebogileclaragumbi4297]

This was helpful thank you

[@lidyah9862]

Thank you! Best explanation!!!

[@francismngumi5125]

Good

[@Ortho1974]

Why delete plate 6 &plate 7? Why not choosing the average result of plate 5-6-7?

[@smitshah8074]

thank you

[@ashleyfincannon2026]

Thank you!

[@inammakhabana6540]

thank you so much, this was very helpful

[@gwendolyngreen]

Helpful! Thank you!

[@ilaila3504]

you are a star thankyou xxxx

[@corradoblondi9792]

Sometimes the simplest things are the more difficult to get to understand.

[@vodhiambo]

This is great

[@harshdeep7628]

In tube no. 6 it should be 1/6 , bcz 2+4 = 6....rest you explained very well

[@MA-jw2qe]

Thank you very much! I would ask, should we always transfer 0.1 ml to the plate? or can I transfer the same volume that was transferred between each tube of dilutions? I hop you get my question

[@ProfGillesBolduc]

You can transfer any volume on a plate. But anything more than 0.1 ml might add too much liquid to the plate and the bacterial colonies may run into each other as they grow. This makes it difficult to count them efficiently. I generally like to use a volume between 0.05 - 0.1 ml.

[@bankingpreparation4926]

Thank you very much sir.

[@nanorizkipratama8004]

Thank you Sir

[@samwatkins4807]

very helpful!

[@linkonpaul07]

During the time between 9-10 min for the dilution series, if you add 1 ml in 9.9ml of culture, the factor is 1/10?? or do you mean 0.1 ml in 9.9ml!!! Please let me know, if i am wrong?

[@ProfGillesBolduc]

That is not correct. 1ml (from tube 1) was added to tube 2 (containing 9ml). Tube 2 was mixed a bit and 0.1ml from tube 2 was than added to tube 3 (containing 0.9ml).

[@ruisucepi]

Thank you very much

[@allenlinatoc9177]

Thank you so much

[@ongyj2206]

What if I have 3gram of solid sample, can I add up 7ml of sterile water, then subsequent dilution using 1ml transfer.. The final dilution factor would be like this? 0.7 -> 0.07 -> 0.007 -> 0.0007 -> 0.00007 -> ....

[@avyarasikka709]

ok what if two plates have cfu which falls in the range 30 to 300 ? Which cfu to take for calculation ? Do we take average ?

[@ProfGillesBolduc]

Good question. You would use both plates to calculate your answer, then average the two for a better answer.

[@anasali2566]

On which base you multiply 91 by 10000... Kindly Sir explained...????

[@sitinursyahirah6380]

but why for tube 6 only added 2.0ml?

[@raneemkhlel2982]

thanks a lot

[@allenlinatoc9177]

Thank you so much ❤️❤️❤️

[@tyrionlannister8]

How did he get 0.1ml when he’s calc. 91 Cfu per ml?

[@anuranjanekka7478]

Thankyou..😊