Dear list members

I am checking the protocols for cystine-cysteine and as I can see each author uses different times to reduce -S-S to -SH. for example:

pearse 1985: 4 hours at 37#186# in 0,5 M thyoglycollic acid pH 8

Vacca 1985: 2 - 4 hours at 50 #186# in thioglycollic acid 2,4 %

Kiernan 1990: 15 minutes in 5 % thioglycollic acid

Barka & Anderson: 1-2 hours at 50-60#186# in 0.2 - 0.5 M thioglycollic acid pH 8 or overnight with thioglycerol 5-6 % at 37#186#

Can you tell me what of this is the best time- temperature to obtain the complete reduction of the -S-S- ?

Thanks in advance

Jos#233# Luis