Fig. 6.
Amyloid-β (Aβ) peptide recovery from cerebrospinal fluid (CSF) aliquoted into Axygen MAXYMum Recovery® or Eppendorf LoBind® tubes following guanidine hydrochloride (GuHCl) denaturation before tube transfer (gray bars) or after transfer to a new tube (white bars) as measured by 2D ultraperformance LC-MS/MS. a and b Aβ1–42 and Aβ1–40 concentrations were significantly higher (p ≤ 0.05) when pooled Alzheimer’s disease CSF from four patients was denatured with GuHCl in the original Axygen MAXYMum Recovery® aliquot tubes before analysis (Axygen, gray bars) when compared with concentrations recovered from CSF denatured with GuHCl after removal from the original aliquot tube (white bars). Aβ1–42 and Aβ1–40 concentrations from the same CSF pool were higher when measured from Eppendorf LoBind® tubes, regardless of the timing of GuHCl treatment. c–e Aβ1–38, Aβ1–37, and Aβ1–34 concentrations were not significantly impacted by tube type or GuHCl pretreatment. *p ≤ 0.05, NS = not significant (p > 0.05)