title: Saliva sampling method affects performance of a salivary α-amylase biosensor.
abstract: OBJECTIVE
  Prompted by the discordance between a standardized salivary alpha-amylase (sAA) biosensor applied in clinical settings and a reference laboratory analyzer, we examined the impact of the saliva sampling method on the analytic performance of the biosensor.
  
  
  METHODS
  Direct mouth readings using the biosensor from 31 normal, healthy volunteers were compared to biosensor and conventional assay readings obtained from saliva samples collected concurrently by passive drool and processed in three different ways (unprocessed, thawed, and thawed and centrifuged).
  
  
  RESULTS
  The direct readings from the mouth showed consistently lower sAA values (Ps < 0.01) compared to all other combinations of sample processing and quantification platforms (biosensor vs. conventional assay). Readings obtained from passive drool saliva were strongly correlated with one another, and Bland-Altman plots of agreement indicated a smaller discrepancy between conventional and biosensor readings obtained with passive drool when compared to the direct mouth readings.
  
  
  CONCLUSIONS
  Our study indicates that the analytical performance of the sAA biosensor is influenced significantly by the saliva sampling method. In contrast to the relatively imprecise direct mouth measurements, biosensor sAA levels established indirectly from passive drool saliva samples provide more accurate estimation of sAA levels, even after intermediary processing steps (e.g., freezing, thawing, centrifugation).
authors.affiliation: Department of Psychology, University of California, Los Angeles, Los Angeles, 90095-1563, California.
authors.forename: Theodore F
authors.initials: TF
authors.lastname: Robles
authors.forename: Rassilee
authors.initials: R
authors.lastname: Sharma
authors.forename: Lauren
authors.initials: L
authors.lastname: Harrell
authors.forename: David A
authors.initials: DA
authors.lastname: Elashoff
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Vivek
authors.initials: V
authors.lastname: Shetty
mesh_terms: D000328:Adult; D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D012463:Saliva / Q000737:chemistry*; D055291:Salivary alpha-Amylases / Q000378:metabolism*; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult
chemical_list: D055291:Salivary alpha-Amylases