On the eve of this Christmas evening, i was reading my Molecular biology book and just after finishing my sub unit , "Semi conservative mode of DNA replication " i opened RU-vid and this was the 1st recommendation video , Am so much fortunate that i am watching these two novel laureates . Respect from India 🤝🤝🤝
I worked as Matt Meselson's research asst. when he first came to Harvard, 1961 until 1965. He was a great person to work for/with. We used the density gradient technique for further phage genetics studies. The woman I worked for at Caltech, where my husband was an undergrad, Hildegarde Lamfrom suggested Dr. Meselson hire me, a we were going to Harvard too. He wanted someone willing to learn his careful techniques.
OMG, I learned this in high school. Absolutely beautiful and elegant experiment, and to see the real people behind this experiment brings so much emotion. Now as a cell biologist, revisiting this experiment on here just makes me so proud of being a part of this incredible field of biology. Someone has said to me "the most beautiful experiment is usually the simplest one of all" and this is an example.
At their time they thought they were graduate students and looked up to Richard Feynmann and Linus Pauling as great scientists. For students today they are the same for us.
I am grateful to know two of our most respected scientists who have confirmed the Watson-Crick model are still amongst us. Studying microbiology in this period of scientific development it’s hard to believe that the founding fathers of the DNA model are still alive, thank you for loving science and helping it grow. Stay healthy, and stay safe. Thank you 😊
Studied their experiment in 11th grade, and i remember how bad i too wanted to perform it by my self. Unfortunately couldn't do it at school level. Watching these guys today, surely made the experiment even more BEAUTIFUL for me.
This is so so so beautiful. Wish there was more content like this on the internet. The world is run by the scientists working day and night and not the celebrities dancing with the sharks. Scientists need more respect and exposure.
recall when a grad student and a professor (David Denison) told us a story about when he was a grad student at Caltech when they came into the grad student lounge with an autorad fresh from the experiment
I hope you could get to interview other known scientists/legends like them :) very nice interview.. it made me remember my super smart 75 year-old professor in my graduate studies :’)
Wow! Just wow. This is the most wonderful thing I've seen in a long time. Thank you for bringing these two together and having them share their work and friendship with us. This is a treasure.
Sir, you both are so adorable... Literally feeling on the top of the world cause of being able to learn your experiment by yourself. It not just the experiment it's also the history, scenario interest.. That ended up to the experiment and this is beyond textbooks truely fortunate..
This type of video should be shown in schools and universities/colleges to encourage students to research. It feels like two grandpa telling the story of their youth.
These were the most beautiful 22 minutes. I really loved the video and do good to see them alive and talking about how they made it through and introduced the concept of semi-conservative replication to the world. So thankful to these men.
THIS SHIT WAS SO CUTE ITS MAKING STUDYING MOL BIO AND GENETICS WORTH IT. But I'm genuinely grateful for their work. It's the foundation of essentially everything I'm learning. I was initially planning on going for med school, but after seeing their work, I'm really interested in studying molecular biology and genetics further, and making my own (very small but still existant) contributions to that field.
You both are our inspiration ❤️ Never thought I would be able to hear this explanation directly from Meselson and Stahl .... Really I am lucky and grateful 💫🙌💝
I kinda hated these names because I didn’t get it and had to know the experiment for my next class test, but these guys are such wholesome grannies lol you can’t not like them
It's amazing how Professor Stahl hasn't changed much since I last saw him in 1996! Wish you well Frank and thank you for the opportunity of letting me work in your lab as an undergraduate- It was really a life-changing experience!
I am so lucky to have atleast watch them on RU-vid. I wish I can meet them in person. The talk was so enriching with humour, insights from those times and just the pure innocence of them. It made my day!!! Thank you iBiology for this great content. Can't thank you enough. ❤️❤️
I stumbled across this talk looking for inspiration for my own online teaching and saw your comment - hope you're well Jean! I still have one of your drawings on my office wall! Good memories of Eugene OR.
@@niabryant406 HI Nia! Nice to hear from you, in this roundabout way! I'm doing well, though sad we couldn't come visit the family, this summer..I was fortunate to have squeezed in a visit in February, before Covid hit, while they were filming this video. Hope you are doing well, too, and that you found some inspiration here for your work! If you are ever in Mexico, come visit us in Oaxaca!
Thank you so much iBiology for providing this amazing interview with two of my scientist heroes. When learning about semiconservative DNA replication, first at school and then again at university, I never thought I'd be able to see Meselson and Stahl in an interview.
Just wow...glad to listen to these 2 geniuses...they seem best buddies & so nostalgic remembering all that stuff...just observe their great sense of humour... it's delightful to see them explain all that in person... how beautifully presented...! Thanks 😇❤️ Please bring more such interesting scientific videos.
My day couldn't be any better than this, watching our legends alive, healthy and reminiscing their journey of experiment! 🤩 I feel so lucky to be a biology student!
WoW! I haven't been this surprised since seeing a talk from Dr. Watson on your channel! makes you think, most of what we know about biology is fairly recent.
I mean....Meselson, Stahl, Fynmann, Watson, Creek all these great people at a place....what an atmosphere must have been there...one can only imagine now.🔥❤️🙏
I was unaware that they're alive, it's such an honour to see you sir! Regards from me, big fan of your work! Thank you so much for this video. I'm very grateful to encounter this video.
Thank you so much for the video. We are Thankful their beautiful and lovely experiment. It's a very pleasant feeling to see them. May they live for a long...... .
Can someone please tell me how did they know exactly one generation of division/DNA replication had occurred? How do you distinguish two generations of replication from say one or three or more? Also, what do generations 0.7 or 1.9 mean? Thanks a lot!
Generation time of the specific bacterium bro! For example E.coli divides every 15 to 20 mins. Generation 0.7 means 10.5 mins and generation 1.9 means 28.5 mins for E.coli (assuming generation time to be 15 mins).
@@arunkumars6257 Thanks for your reply. My doubt mainly was, is the generation time information sufficient in this case/experiment. Because different bacteria will be in different stages of it's cycle and they are not synchronized. So, not all of them will divide after 15 minutes so we should end up with a smear on the density gradient picture, right?
@@SrinivashM29 I guess some optimisations before experimentation might solve this issue. Think of the lag phase all bacteria faces whenever they are exposed to new environment, that might synchronize their growth. Likewise heavy N and light N medium might work in synchronizing their growth.
I thought that they at least might have attempted to synchronize replication by culturing bacteria till stationary phase or at low temperature, but just realized that they hadn't done anything. Take a look at this www.ncbi.nlm.nih.gov/pmc/articles/PMC1307605/
@@volkanergin521 Thanks a lot for the link. It throws a lot of light into the actual experiment. From the link: 'Fragments that had a strand with a transition point from heavy to light and would thus have 'non-quantized' density would have been very rare (1 per 200) and thus not visible in the caesium chloride density gradient.' Can you please explain why these intermediate fragments would be very rare?
What a thoroughly enjoyable video! I had so much fun watching it. Biology is cool and it has always been cool. I am glad these guys were around to contribute to our collective understand of life.
@16:27, the dispersive model would predict that after two replication cycles, every strand of DNA should contain about 25% ¹⁵N and about 75% ¹⁴N. So that should be all the same weight
The intensity with which they felt the beauty of it all must have been so grand. Just hearing them talk about it is so overwhelming that I teared up. Probably because of how well they lend us their senses to be able to soak it all in through their expression.
Brilliant! 😄. I feel so fortunate to have found this video and the channel behind it. I have attempted to be a science communicator my whole life. I don't have all of the math, but I do have the intrinsic fascination with the nature of reality and our universe.... Thank you!
Atomic physics is a result of Darwinian evolution. Thats why Cellular Biology and Atomic Physics share the same theme Units comprised of a nucleus shrouded within a shell, and the capacity to bond with like units and build bodies. This depicts cellular biology just as readily as it depicts atomic physics. Do you need a bigger clue than this?
Why do people think that putting annoying music behind people talking about discoveries enhances the video. It just makes it harder to hear what they are talking about.
