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Setting cutoff concentrations for immunoassay screening of postmortem blood.
J Forensic Sci. 1998 Mar; 43(2):390-4.JF

Abstract

The objective of this study was to establish the optimum immunoassay cutoff concentrations for screening postmortem blood from coroner's cases for drugs of abuse with a coated tube radioimmunoassay (RIA) to ensure that the results with the coated tube RIA would be equal to or better than those with the previously used double antibody RIA. Immunoassay results (positive or negative) blood were compared to confirmed results on those cases by GC/MS alone or in combination with GLC using either a NPD or FID detector. Four to seven potential cutoff concentrations were evaluated for the drug classes opiates, amphetamines, cocaine and metabolites, and barbiturates. Specimens were 350 postmortem blood specimens and liver homogenates. The cutoffs chosen for the coated tube RIA using this approach were 5 ng/mL morphine, 25 ng/mL methamphetamine, 500 ng/mL benzoylecgonine, and 500 ng/mL secobarbital. These cutoffs corresponded to a sensitivity and specificity of 94% and 96% for opiates, 93% and 86% for amphetamines, 91% and 96% for cocaine and metabolites and 91% and 87% for barbiturates. The double antibody RIAs were run on the same specimens with cutoffs of 20 ng/mL morphine, 50 ng/mL methamphetamine, 50 ng/mL benzoylecgonine and 1000 ng/mL phenobarbital. The sensitivity and specificity's for the double antibody immunoassay were: > 99% and 96% for opiates, 83% and 89% for amphetamines, 98% and 97% for cocaine, 79% and 95% for barbiturates.

Authors+Show Affiliations

Forensic Science Services, Santa Ana, CA, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

9544549

Citation

Collison, I B., et al. "Setting Cutoff Concentrations for Immunoassay Screening of Postmortem Blood." Journal of Forensic Sciences, vol. 43, no. 2, 1998, pp. 390-4.
Collison IB, Spiehler VR, Guluzian S, et al. Setting cutoff concentrations for immunoassay screening of postmortem blood. J Forensic Sci. 1998;43(2):390-4.
Collison, I. B., Spiehler, V. R., Guluzian, S., & Sedgwick, P. R. (1998). Setting cutoff concentrations for immunoassay screening of postmortem blood. Journal of Forensic Sciences, 43(2), 390-4.
Collison IB, et al. Setting Cutoff Concentrations for Immunoassay Screening of Postmortem Blood. J Forensic Sci. 1998;43(2):390-4. PubMed PMID: 9544549.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Setting cutoff concentrations for immunoassay screening of postmortem blood. AU - Collison,I B, AU - Spiehler,V R, AU - Guluzian,S, AU - Sedgwick,P R, PY - 1998/4/17/pubmed PY - 1998/4/17/medline PY - 1998/4/17/entrez SP - 390 EP - 4 JF - Journal of forensic sciences JO - J. Forensic Sci. VL - 43 IS - 2 N2 - The objective of this study was to establish the optimum immunoassay cutoff concentrations for screening postmortem blood from coroner's cases for drugs of abuse with a coated tube radioimmunoassay (RIA) to ensure that the results with the coated tube RIA would be equal to or better than those with the previously used double antibody RIA. Immunoassay results (positive or negative) blood were compared to confirmed results on those cases by GC/MS alone or in combination with GLC using either a NPD or FID detector. Four to seven potential cutoff concentrations were evaluated for the drug classes opiates, amphetamines, cocaine and metabolites, and barbiturates. Specimens were 350 postmortem blood specimens and liver homogenates. The cutoffs chosen for the coated tube RIA using this approach were 5 ng/mL morphine, 25 ng/mL methamphetamine, 500 ng/mL benzoylecgonine, and 500 ng/mL secobarbital. These cutoffs corresponded to a sensitivity and specificity of 94% and 96% for opiates, 93% and 86% for amphetamines, 91% and 96% for cocaine and metabolites and 91% and 87% for barbiturates. The double antibody RIAs were run on the same specimens with cutoffs of 20 ng/mL morphine, 50 ng/mL methamphetamine, 50 ng/mL benzoylecgonine and 1000 ng/mL phenobarbital. The sensitivity and specificity's for the double antibody immunoassay were: > 99% and 96% for opiates, 83% and 89% for amphetamines, 98% and 97% for cocaine, 79% and 95% for barbiturates. SN - 0022-1198 UR - https://www.unboundmedicine.com/medline/citation/9544549/Setting_cutoff_concentrations_for_immunoassay_screening_of_postmortem_blood_ L2 - https://www.who.int/reproductivehealth/publications/cancers/a92126/en/ DB - PRIME DP - Unbound Medicine ER -