Question

Question Posted 06/14/17:
Hi,

I am currently working on an MJFox funded project to investigate the differences between PPMI and ADNI sample collection/processing protocols on CSF levels of Aβ42, t-tau, p-tau181, α-syn and ps129 and subsequently develop conversion models if needed. While we have all the information we need from PPMI and ADNI regarding collection procedures, what we don't have is subaliquoting protocols from ADNI. What we'd like to know is what happened to the samples post collection and prior to running assays. Specifically, how the samples were handled, the types of tubes used and the volume of subaliquots prepared.

Hope you can help.
Regards,
Anzari Atik, PhD
Senior Fellow, Zhang Lab
Dept. of Pathology, University of Washington
Response posted 06/20/17 by Les Shaw:
Dear Dr Atik, thank you for your question. The protocol for the ADNI CSFs upon receipt in the ADNI BIomarker Core laboratory is as follows:
The two tubes of CSF, shipped overnight on dry ice, are stored temporarily at -80 0C. On the day of aliquot preparation, the usual two tubes are thawed at room temp over a 30 minute period of time and then gently poured into a 30 mL polypropylene tube (Sarstedt 62.543.001) and gently mixed for 10 minutes. Aliquots are prepared from this CSF using a polypropylene pipet tip (Biohit cat.# 791000. Aliquot size is 0.5 mL and these are pipetted into 0.5 mL polypropylene aliquot tubes (Nalgene #967-21613).

A cautionary note for you regarding development of conversion models: unless you are prepared to use at least 50 different patient CSF collections using the two protocols it will be very difficult to accurately predict expected values for abeta42 at least. Happy to discuss this further if you wish. My office #: 215-662-6575.

Les Shaw