title: Pre-clinical validation study of a miniaturized electrochemical immunoassay based on square wave voltammetry for early detection of carcinoembryonic antigen in human serum.
abstract: BACKGROUND
  The ELISA format for measuring carcinoembryonic antigen (CEA) serves as a reference standard against which other assays are compared. Because the World Health Organization (WHO) increasingly recommends the use of serum CEA as a diagnostic tool for cancer, it is relevant to explore the reliability of the new decentralized CEA point-of-care-testing (POCT) technologies that are available to physicians and patients, in compliance with mandates of the clinical laboratories' regulatory agencies.
  
  
  METHODS
  Electrochemical immunoassay (ECIA) based on trace lead (Pb) analysis by anodic stripping techniques using sandwich-type immunocomplex conjugates: (MB)Ab/AgCEA/Ab(PbS), and a commercial ELISA test system with optical transmission.
  
  
  RESULTS
  The ECIA provides better analytical performance than does the ELISA. The within assay precision coefficient of variance (%CVw) of the ECIA is lower than the value recommended by the Hong Kong Association of Medical Laboratories (HKAML), and the recoveries of CEA at 1.0, 5.0, 10.0, 25.0 and 50.0 ng/ml are in the range of 99-110% for control serum samples. The ECIA showed a minimal positive bias of 0.0267 ± 0.3270 ng/ml (P=0.9389).
  
  
  CONCLUSIONS
  The proposed CEA screening technology can be practically employed for decentralized clinical analysis of CEA in human serum. Therefore, it can be viewed as a control method for personalized therapy.
authors.affiliation: Centro de Investigación y Desarrollo Tecnológico en Electroquímica, S.C., Parque Tecnológico Querétaro S/N, P.O. Box 064, Pedro Escobedo, Querétaro C.P. 76703, Mexico.
authors.forename: Flavio Dolores
authors.initials: FD
authors.lastname: Martínez-Mancera
authors.affiliation: Instituto Nacional de Cancerología, Av. San Fernando No. 22, Col. Sección XVI, Del. Tlalpan, México, D.F., C.P. 14080, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: García-López
authors.affiliation: Centro de Investigación y Desarrollo Tecnológico en Electroquímica, S.C., Parque Tecnológico Querétaro S/N, P.O. Box 064, Pedro Escobedo, Querétaro C.P. 76703, Mexico. Electronic address: jhernandez@cideteq.mx.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Hernández-López
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D056808:Biostatistics; D002272:Carcinoembryonic Antigen / Q000097:blood*; D055088:Early Detection of Cancer; D055664:Electrochemical Techniques / Q000295:instrumentation; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation; D006801:Humans; D010316:Particle Size; D013499:Surface Properties
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen
keywords: Biostatistical analysis; Carcinoembryonic antigen; ELISA test system; Magnetic beads; Miniaturization; Square wave voltammetry