Page 1 of 1

L-Buffer alternative

PostPosted: Fri May 17, 2024 1:23 pm
by mds4z
Hello

We are in need of extra L-buffer. Were told can't purchase this individual, only with kits from Biotools. Is there an alternative source, or recipe to make your own?

Thanks
Mike

Re: L-Buffer alternative

PostPosted: Fri May 17, 2024 3:15 pm
by DMcDonald
Hi Mike,

I've a sneaky suspicion it's just 150 mM sodium phosphate pH7.2. I could be wrong but it's from this paper which describes a near identical conjugation and I've always assumed the original DVS kit spawned out of: https://pubmed.ncbi.nlm.nih.gov/20939532/

I've never tried the switch though.

David

Re: L-Buffer alternative

PostPosted: Fri May 17, 2024 3:57 pm
by ezunder
Hi,

David- I think what you put here is the R-buffer, not the L-buffer, right? The paper you cited is great! They use 150 mM sodium phosphate buffer at pH 7.2 as an R-buffer (reducing) for the TCEP step. The L-buffer (loading) is 20 mM ammonium acetate at pH 5.2. This is used for DTPA/Lanthanide incubation.

If I recall correctly, we never had to pH the ammonium acetate because it was around pH 5-6 after dissolving in water. The low pH helps prevent metal oxidation I think.

I vaguely remember hearing that DVS/Standard Biotools switched away from using Ammonium Acetate as their L-buffer, but this may just be hearsay :)

We always used L-buffer for metal storage as well as DTPA loading. I bet that Ammonium Acetate is still good for DTPA loading, but maybe they found something better for long term storage?

Mike- if you decide to use Ammonium Acetate for L-buffer, I would buy the purest you can find from Sigma-Aldrich and definitely run a small aliquot in liquid mode to make sure there's no contaminating metals before using it for antibody conjugations! :)

Best,
Eli

Re: L-Buffer alternative

PostPosted: Fri May 17, 2024 4:06 pm
by DMcDonald
Hi Eli, Yes you're right I've got them switched!

Re: L-Buffer alternative

PostPosted: Fri May 17, 2024 4:19 pm
by CRStevens
Mike,

My first question to you is do you believe L-buffer has an expiration date. I have some vintage L-buffer. I'm not sure if it is like wine that gets better with age but let me know how picky you are.

-Chad