Virus Watch: Counting Viruses

What an amazing demonstration !!
Could you please make a demonstration on quantifying bound-virus on a Staphylococcal cell wall?

I am eagerly waiting for your reply.

Excellent 👍

Great Work Prof. Racaniello.. thank you for teaching us

i like olio virus too!!!1!!1!!1

Very helpful and informative video 👏👏

Your explanations and tutorials worth more than a $4000 course I have done locally before knowing your channel and subscribed :-). Great thanks Vincent

Professor, you don't autoclave the TSA agar?

thank you

Does one virus infects only one host-cell? Or can multiple viruses attack the same cell? Can this interfere with the calculation of PFU/ml?

And why is it usually used a 6 well plate? Specially if you dilute to -8.

Why plaque assay and not TCID50?

Virologists or student virologist please my question.

Is the 'virus sample', isolated, purified, visualised, and its morphology and genetic sequence described BEFORE adding it to a cell culture?

If this is not done, the process seems very anti-scientific. I find it very interesting that a virus is never identified directly from a sick person.

Bravo, Dott. Racaniello!! 👏🏻👏🏻 and of course, Dr. Amy too!

This was EXTREMELY helpful! Thank you for your help!

Excellent presentation🤩🤩

Very impressive wall!

Excellent presentation, Professor!

👌👌👌

PCR is not meant for virus count. It multiplies exponentially whatever it's set to multiply. We use it for sequencing. That's it's primary purpose.
A 96 well assey where 50% are dead is best suited for establishing viral titer.

Didn't realize Robin Williams was a virology professor

I’m studying for my Virology class, and this was helpful. Interested in seeing more science videos from you. Subscribed. : )

Hello!! Mr Vincent

I am a student of Colombian Microbiology. This video is so great. Could you tell me what other solution I can use to remove the agar from the plate safely and what is the concentration? I appreciate it a lot. Good vibes.

So great!!!

We are onto your 'scientific' fraud. Might as well be baking bread with litmus paper in it. Fools!!

so you're just measuring alkalinity for the color? That's not measuring a virus. Get real

so basically you count dead cells...not viruses. get real

''If I held up this tube and asked you how many zika viruses were in it?'' ----I would say probably you are holding up a phial of pink koolaid as a prop for the show. Be real.

You the Best !

We need special glove to protect forearm skin

It is a pretty wall

Since you mentioned polio i would like to know your thoughts on the polio vaccination being contaminated with cv40 or monkey cells?

Ha ha, you said counting the virus titre is easy. In recent podcasts you get all 'grumpy' when people talk in terms of virus titre

Ah! Now I understand some of the PCR vs. need-for-plaque-assay discussion re: post-recovery SARS CoVi-2 'virus' or RNA measurements in recent TWiVs! Thanks, Vincent, for the clear explanation.

i haven't heard anybody said so well about a tedious process. Great Sir

Thank you so much for sharing your experience

excellent sir, so clear and understandable for layman as well, informative and to the point, thank you.

Thanks! Is this method the same for marine bacteriophages?

Extremely well paced and presented. Thank you so much!

Excellent vid, Tnx.

Thank you

Thanks for the video! very simple for understanding this method

Thank you.

Fantastic explanation! GREAT JOB!

Awesome video. Thank you

Thank you!

Thank you so much

This was the best, most comprehensive explanation I could find of plaque assays, thank you so much!!

Is determining the infectious:noninfectious ratio used to identify the virus species or just study the properties of a particular strain?

If the former, what about flow cytometry?