title: Detection of castor contamination by real-time polymerase chain reaction.
abstract: Due to the potential for intentional contamination of food with crude preparations containing ricin, a real-time PCR method was developed for the detection of castor plant material in ground beef. One primer pair was identified and confirmed to be castor-specific and efficient for amplification of ricin in DNA extracts from castor or beef matrices. Of three different DNA extraction protocols compared, the hexadecyltrimethylammonium bromide (CTAB) method yielded the highest quality of DNA for QPCR assay. The detection limit for castor contamination in ground beef samples was <0.001% (<10 microg of castor acetone powder per gram of beef, corresponding to 0.5 microg of ricin), indicating excellent sensitivity for the assay, well below the threshold for oral toxicity.
authors.affiliation: Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, USA.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: He
authors.forename: David L
authors.initials: DL
authors.lastname: Brandon
authors.forename: Grace Q
authors.initials: GQ
authors.lastname: Chen
authors.forename: Thomas A
authors.initials: TA
authors.lastname: McKeon
authors.forename: John Mark
authors.initials: JM
authors.lastname: Carter
mesh_terms: D000818:Animals; D002367:Ricinus communis / Q000737:chemistry / Q000235:genetics*; D002417:Cattle; D018744:DNA, Plant / Q000032:analysis; D005506:Food Contamination / Q000032:analysis*; D008460:Meat / Q000032:analysis; D016133:Polymerase Chain Reaction; D012276:Ricin / Q000032:analysis / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: D018744:DNA, Plant; D012276:Ricin