Hello,

I was wondering if you have tried reconstituting the NH4OH treated amyloid beta in 1% NH4OH as suggested by several of the manufacturers when reconstituting it for the first time (Anaspec, Sigma) instead of 60 mM NaOH? Similarly, have you tried using smaller concentrations of NH4OH than 10% for lyophilisation?

Best wishes,

Veronika

Hi Ryan,

I have another question regarding amyloid lyophilization. Recently, we bought Labconco 2.5L, -84°C benchtop lyophilizer and I tried to lyophilize amyloids with it. I prepared amyloids with NH4OH method. Basically, I added 1ml of 1% NH4OH solution to 1mg of amyloid beta (1-42), I mixed it slightly by hand, to dissolve it. Then I sonicate solution at RT for 5 min, aliquote into 50ul aliqu...

Hi, I would like to know your protocol for amyloid beta lyophilization. I've found some people that have a lyophilizer, which will lyophilize my protein for me, but they have asked about the conditions that they should use. I haven't use lyophilizer before, so I don't know what kind of temperature, pressure and other conditions should be use. Can you share your amyloid beta lyophilization protoco...

i plan to use ammonium hydroxide for pre-treatmennt. may i know after lyophilisation, how long it can be stored in -80? is it soluble in PBS only? because im going to introduce this compound directly on brain.. so i would like to avoid using mixture of Naoh + sterile water..

What happened when Abeta was incubated in NH4OH for longer? Also, did you check if there was any epimerization of the peptide?

I wonder which stage of amyloid beta 42 can be monomerized.

Can fibril also be monomerized? or only oligomer stage can be monomerized?

Thank you for your kind answer :)

I have one more question.

As you told me, I use freeze-dryer.

I put my recombinant amyloid beta into the machine. And I checked after more than 40h.

However, it was not powder form but the solid form like sticky candy.

Now I think that this machine can only do the first dry... Should I do the secondary drying with heating?

(The temperature of cha...

I use my recombinant peptide which is purified from E.coli. It has extra sequence. I use more HFIP than protocol but it did not dissolve. And I am confused about lyophilization. Because after finishing the procedure my sample tube is warm, maybe 40 celsius degree. I have used speedvac. Can I use this constantly?

1. I have read your paper, but I still feel at a loss about the method of generating small toxic oligomers in vitro. Which concentration do I need to dilute the 200 μM of Aβ stock solution? If I diluted the stock solution, how long and which temperature to make soluble oligomers?
2. If I reconstitute Aβ-42 in 60mM NaOH to a stock concentration of 200 μM, how to store this solution?...