As for making HEPES buffers, it’s common to make a 1M stock solution. To do so you usually dissolve the free acid form (238.3 g/L) in a partial volume and then take away protons by adding in a strong base (in the form of NaOH or KOH depending on which of these counterions you want hanging around). It will take a lot, so it can be good to start with pellets of the base and then switch to a concentrated solution to do the final adjustments. Much more on making buffers here: th-cam.com/video/jJBbCj3Kz7c/w-d-xo.html Further reading: Ferreira, C., Sousa-Pinto, I., Soares, E. V., Soares, H. M. V. M. (2015). (Un)suitability Of the Use Of Ph Buffers In Biological, Biochemical And Environmental Studies And Their Interaction With Metal Ions - A Review. RSC Adv., 39(5), 30989-31003. doi.org/10.1039/c4ra15453c The components of the cell culture medium: HEPES, December 15, 2021, CellCulture, cellculture.altervista.org/the-components-of-the-cell-culture-medium-hepes/?doing_wp_cron=1686487460.1280500888824462890625 Effect of temperature on pH: Häring M, Pérez-Madrigal MM, Kühbeck D, Pettignano A, Quignard F, Díaz DD. DNA-Catalyzed Henry Reaction in Pure Water and the Striking Influence of Organic Buffer Systems. Molecules. 2015; 20(3):4136-4147. doi.org/10.3390/molecules20034136
more about all sorts of things: #365DaysOfScience All (with topics listed) 👉 bit.ly/2OllAB0 or search blog: thebumblingbiochemist.com
Thank you for this video! Do you have thoughts on using hemisodium powders of HEPES? I came across SKUs for it (1/2 HEPES and 1/2 HEPES sodium salt), it's supposed to already be at pH 7.5! Maybe it helps with media prep (less need to adjust pH)
As for making HEPES buffers, it’s common to make a 1M stock solution. To do so you usually dissolve the free acid form (238.3 g/L) in a partial volume and then take away protons by adding in a strong base (in the form of NaOH or KOH depending on which of these counterions you want hanging around). It will take a lot, so it can be good to start with pellets of the base and then switch to a concentrated solution to do the final adjustments.
Much more on making buffers here: th-cam.com/video/jJBbCj3Kz7c/w-d-xo.html
Further reading:
Ferreira, C., Sousa-Pinto, I., Soares, E. V., Soares, H. M. V. M. (2015). (Un)suitability Of the Use Of Ph Buffers In Biological, Biochemical And Environmental Studies And Their Interaction With Metal Ions - A Review. RSC Adv., 39(5), 30989-31003. doi.org/10.1039/c4ra15453c
The components of the cell culture medium: HEPES, December 15, 2021, CellCulture, cellculture.altervista.org/the-components-of-the-cell-culture-medium-hepes/?doing_wp_cron=1686487460.1280500888824462890625
Effect of temperature on pH: Häring M, Pérez-Madrigal MM, Kühbeck D, Pettignano A, Quignard F, Díaz DD. DNA-Catalyzed Henry Reaction in Pure Water and the Striking Influence of Organic Buffer Systems. Molecules. 2015; 20(3):4136-4147. doi.org/10.3390/molecules20034136
more about all sorts of things: #365DaysOfScience All (with topics listed) 👉 bit.ly/2OllAB0 or search blog: thebumblingbiochemist.com
Really good video! Thank you for your effort!
Thank you!
Thank you for this video! Do you have thoughts on using hemisodium powders of HEPES? I came across SKUs for it (1/2 HEPES and 1/2 HEPES sodium salt), it's supposed to already be at pH 7.5! Maybe it helps with media prep (less need to adjust pH)
That can be a great option! I would just make sure to check the pH
Truee - do you use a pH probe to check? I was wondering about pH strips or just watching the phenol red color 🫢
Yes - I would use a probe