Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidime...Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidimetric assay forβ2-MG as the research object,β2-MG levels were detected by different concentration gradients ofβ2-microglobulin samples in Liedemann,Mack,and Myriad reagents of three manufacturers on two automatic biochemical analyzers,and the difference of the hook effect was comparatively analyzed.Results:Leadman reagent showed the hook effect on the Beckman AU5800 automated biochemistry analyzer,while both Maccura and Mindray reagents did not show the hook effect.After the experiments,we found the limit value of the pre-zone check of Leadman reagent,and changed the parameters of the instrument,when the limit value of the pre-zone check was reached,the instrument automatically diluted the specimen five times and then detected it again.After changing the parameters of the instrument,the correlation between the three methods of detecting samples of different concentrations was r>0.99.Conclusion:Before selecting the application of immunoturbidimetric reagents,we have to carry out the risk assessment of the hook effect and selectively set the parameters of the pre-zone check based on the highest concentration that may occur in the clinic;for the items that may have the hook effect,we have to selectively set the parameters of the pre-zone check when the ratio of average reaction rate and the immediate reaction rate is at the limit value,and the phenomenon of antigen excess may occur,the instrument will carry out automatic dilution before detection,so as to avoid the issuance of erroneous results of high-value samples due to the hook effect.展开更多
The hook effect is best explained by how the analyte signal generated from the assay is compromised due to either antibody excess or antigen excess.Reporting false negatives can also impact clinical decisions that may...The hook effect is best explained by how the analyte signal generated from the assay is compromised due to either antibody excess or antigen excess.Reporting false negatives can also impact clinical decisions that may have adverse effects on the patient.The clinical impact of the hook effect will lead to reporting either inaccurately low or false-negative results.Six different patient pools were tested using immunoassay screening methods and also the LC-MS/MS confirmation method.For the immunoassay screening method,50μL of each patient sample is pooled together for every 100 patient samples.If there is a sample with the hook effect,it would give a very low or a negative result when the pool is tested neat and it would give a positive result when the pool is tested in a 1∶100 dilution.The drugs tested included Cannabinoids,Benzodiazepines,Amphetamines,Ecstasy,EDP,Opiates,Heroin,Cocaine,Fentanyl,Oxycodone and a combined method for Buprenorphine/Norbuprenorphine.Patient Pool number 6 showed a positive Buprenorphine and Norbuprenorphine that was traced back to the sample with the hook effect based on the suggested protocol.The random and different patient pools were prepared by using a Gilson GX241 liquid handler.The neat result for Pool number 6 showed the immunoassay for Buprenorpone and Norpuprenorphine was“Not Detected”at 2.1μg/L while the LC-MS/MS result was 2,780μg/L(cut-off<10μg/L).However,the result for the 1 in 100 dilutions of the pool for the immunoassay was“Detected”at 37μg/L without multiplying by the dilution factor.The result for the LC-MS/MS was 2,970μg/L.The suggested protocol is practical and cost-effective to avoid the clinical impact of reporting either inaccurately low or false-negative results.Also,can be used for testing when suspected samples with the hook effect are investigated.展开更多
SD Twenty adult male rats were equally divided into a contro1 and an experimcntal group.GTW,10 mg/kg per day,was given to the experimental rats through gastric gavage 6 days a week for 8 weeks.To the control rats,the ...SD Twenty adult male rats were equally divided into a contro1 and an experimcntal group.GTW,10 mg/kg per day,was given to the experimental rats through gastric gavage 6 days a week for 8 weeks.To the control rats,the same amount of vehicle was given The animals were sacrificed when they became infertile and the fol1owing parameters of the testis and epididymis were examined:l)DNA(Feulgen′s method),2)RNA(Brachet′s tech-uique),3)LDH-X(Lojda′s method),4)ATPase(Wachstein′s procedure),5)Succinate dehydrc-genase(SDH,Pearson's method),6)Non-specific esterase(NSE,Lojda's technique)and 7)PAS reaction.Routine examination of the epididymal spermatozoa was also carried out.展开更多
基金Baoding Science and Technology Bureau(2141ZF313)。
文摘Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidimetric assay forβ2-MG as the research object,β2-MG levels were detected by different concentration gradients ofβ2-microglobulin samples in Liedemann,Mack,and Myriad reagents of three manufacturers on two automatic biochemical analyzers,and the difference of the hook effect was comparatively analyzed.Results:Leadman reagent showed the hook effect on the Beckman AU5800 automated biochemistry analyzer,while both Maccura and Mindray reagents did not show the hook effect.After the experiments,we found the limit value of the pre-zone check of Leadman reagent,and changed the parameters of the instrument,when the limit value of the pre-zone check was reached,the instrument automatically diluted the specimen five times and then detected it again.After changing the parameters of the instrument,the correlation between the three methods of detecting samples of different concentrations was r>0.99.Conclusion:Before selecting the application of immunoturbidimetric reagents,we have to carry out the risk assessment of the hook effect and selectively set the parameters of the pre-zone check based on the highest concentration that may occur in the clinic;for the items that may have the hook effect,we have to selectively set the parameters of the pre-zone check when the ratio of average reaction rate and the immediate reaction rate is at the limit value,and the phenomenon of antigen excess may occur,the instrument will carry out automatic dilution before detection,so as to avoid the issuance of erroneous results of high-value samples due to the hook effect.
文摘The hook effect is best explained by how the analyte signal generated from the assay is compromised due to either antibody excess or antigen excess.Reporting false negatives can also impact clinical decisions that may have adverse effects on the patient.The clinical impact of the hook effect will lead to reporting either inaccurately low or false-negative results.Six different patient pools were tested using immunoassay screening methods and also the LC-MS/MS confirmation method.For the immunoassay screening method,50μL of each patient sample is pooled together for every 100 patient samples.If there is a sample with the hook effect,it would give a very low or a negative result when the pool is tested neat and it would give a positive result when the pool is tested in a 1∶100 dilution.The drugs tested included Cannabinoids,Benzodiazepines,Amphetamines,Ecstasy,EDP,Opiates,Heroin,Cocaine,Fentanyl,Oxycodone and a combined method for Buprenorphine/Norbuprenorphine.Patient Pool number 6 showed a positive Buprenorphine and Norbuprenorphine that was traced back to the sample with the hook effect based on the suggested protocol.The random and different patient pools were prepared by using a Gilson GX241 liquid handler.The neat result for Pool number 6 showed the immunoassay for Buprenorpone and Norpuprenorphine was“Not Detected”at 2.1μg/L while the LC-MS/MS result was 2,780μg/L(cut-off<10μg/L).However,the result for the 1 in 100 dilutions of the pool for the immunoassay was“Detected”at 37μg/L without multiplying by the dilution factor.The result for the LC-MS/MS was 2,970μg/L.The suggested protocol is practical and cost-effective to avoid the clinical impact of reporting either inaccurately low or false-negative results.Also,can be used for testing when suspected samples with the hook effect are investigated.
文摘SD Twenty adult male rats were equally divided into a contro1 and an experimcntal group.GTW,10 mg/kg per day,was given to the experimental rats through gastric gavage 6 days a week for 8 weeks.To the control rats,the same amount of vehicle was given The animals were sacrificed when they became infertile and the fol1owing parameters of the testis and epididymis were examined:l)DNA(Feulgen′s method),2)RNA(Brachet′s tech-uique),3)LDH-X(Lojda′s method),4)ATPase(Wachstein′s procedure),5)Succinate dehydrc-genase(SDH,Pearson's method),6)Non-specific esterase(NSE,Lojda's technique)and 7)PAS reaction.Routine examination of the epididymal spermatozoa was also carried out.
