Sample Processing is to collect target protein. The processing shall be done as gently as possible as protein denatures or degrades easily. It is also very important to store processed sample, especially avoiding repeated free-thaw cycles. Processed sample can be sub-packed and sealed. Expiry Time: a week at 4 degree; a month at -20 degree; two months at -80 degree. Just put sample in room until its temperature reaches room temperature before using the sample. It is forbidden to heat the sample to melt the sample.
The best time for collecting saliva is when someone has empty stomach. It is hard to collect saliva in half an hour after dinner, because there is much of ptyalin in saliva.
Put sample into centrifuge tube and keep it at -70 degree for an hour. Then thaw it on ice and centrifuge at 10000rpm for 10 minutes. Collect supernatant at last and then test it.