ABSTRACT
Procalcitonin (PCT) is the precursor of calcitonin related to the severity of human bacterial infection. We made a test strip by coupling anti-PCT to quantum dot, in order to develop a highly sensitive and convenient PCT testing product. The anti-PCT titer had reached 10⁷ because of the stability by coupling anti-PCT with quantum dot. The detecting linear range of the experiment was 0.15 to 120 μg/L, the sensitivity was 0.007 μg/L, the recovery range was 91% to 113%, and the intra- and inter-assay coefficient of variation was less than 8%. Comparing the homemade fluorescence-detected test strip with PCT ELISA kit on sale, we got accurate results which could mostly accomplish the test of clinical samples.
ABSTRACT
Objective To make portable the detector for up-converting phosphor (UCP) immune lateral flow assay portable and increase the test precision by developing an area CCD-based detection system for UCP immune lateral flow assay.Methods The excitation light source was a 980 nm and 300 mW laser diode.In order to decrease the error induced by the un-uniformity of laser irradiation,a uniformity mirror was inserted in the beam and a calibration algorithm was optimized.The residual error from the un-uniformity irradiation was less than 1％.Results Thanks to the adjustability of the exposure time,the dynamic range of detection of the system was as high as 106 dB.The repeat test error for the very low signal was 1％ (variation coefficient).The linear correlation coefficient between the tested T/C value and sample concentration was 0.998.Conclusion Compared to is traditional instrument,this detection system is static,portable and highly precise.
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ObjectiveTo investigate the clinical application value of enzyme-linked immunosorbent assay (ELISA) and time-resolved fluorescence analysis(TRFIA) and latex immune chromatography (GICA) in detecting hepatitis B serum markers.MethodsOne hundred and forty-five suspected patients of hepatitis B were detected serum markers of hepatitis B by ELISA,TRFIA and GICA method,and the results were compared and analyzed.ResultsWhen TRFIA method was as gold standard,the positive coincidence rate of ELISA and GICA method in HBsAg,HBeAb,HBcAb was 71％ (57/80),45％ (36/80),and in HBsAb,HBeAb,HBcAb was 33％( 1/3),0 (0/3),and there were significant differences between two methods (P＜0.05 ) ; the others were no significant differences (P ＞ 0.05 ).There was significant difference in the sensitivity of HBsAg between ELISA method and GICA method (P ＜ 0.05 ),but there was no significant difference in HBsAb,HBeAg,HBeAb,HBcAb(P ＞ 0.05 ).There was no significant difference in the specificity of HBsAg,HBsAb,HBsAg,HBeAb and HBcAb between ELISA method and GICA method (P ＞0.05).There was significant difference in HBsAg among three methods(P ＜0.05),but there was no significant difference between ELISA method and TRFIA method (P＞0.05),and there was significant difference between GICA method and TRFIA method (P＜0.05).There was no significant difference in HBsAb,HBeAg,HBeAb and HBcAb among three methods (P ＞ 0.05 ); there was significant difference in both HBsAb and HBeAb positive among three methods (P ＜ 0.05),and there was significant difference between ELISA method,GICA method and TRFIA method (P＜ 0.05).ConclusionTRFIA method has supreme measuring range,sensitivity and specificity supreme,but the price is higher;ELISA method is in the intermediate level of three methods and price is cheap,and it as well as TRFIA is suitable for the batch detection; GICA accuracy is low,but quick and simple,it is more suitable for the complement of the first two methods.
ABSTRACT
Con la finalidad de mejorar el diagnóstico de laboratorio de sífilis como enfermedad infecto contagiosa en donantes de sangre, se realizó el presente estudio cuyo objetivo es determinar las pruebas serológicas específicas: Inmunoanálisis Enzimático (ELISA), Inmunocromatografía (IC) e inespecíficas: Laboratorio de investigación de enfermedades venéreas (VDRL) y Reaginas séricas no calentadas (USR) más confiable para el descarte de sífilis en donantes de sangre del Hospital Dr. Adolfo Pons de Maracaibo, estado Zulia. Se analizaron 481 sueros de donantes de sangre aparentemente sanos, de ambos sexos en edades comprendidas entre 18 y 60 años. Del total de muestras analizadas por ELISA 10 resultaron positivas (2,07 por ciento) y 8 (1,66 por ciento) por IC. El VDRL captó 4 (0,82 por ciento) sueros con reactividad y USR sólo 2 sueros (0,41 por ciento). Se concluye que la prueba de ELISA conjuntamente con el VDRL son las herramientas más seguras y fidedignos para el descarte de sífilis en donantes de sangre, dado que proporcionan en paralelo resultados confiables, fidedigno que garantice la calidad de la misma al ser transfundida
In order to improve the laboratory diagnosis of syphilis as an infectious and contagious disease in blood donors, we performed this study to determine the reliability of the specific: Enzyme Immunoassay (Elisa) and Immune-chromatography (IC) tests, the unspecific: Venereal Disease Research Laboratory (VDRL) test and the Unheated serum regain (USR) Serologic tests to rule out syphilis from blood donors of the Dr Adolfo Pons Hospital in Maracaibo, Zulia state. We analyzed 481 sera from apparently healthy blood donors, male and female, 18 to 60 years of ages. From the samples analyzed by Elisa 10 were positive (2.07 percent) and 8 (1.66 percent) by IC. VDRL detected 4 (0.82 percent) reactive sera and USR just 2 (0.421 percent). We concluded that Elisa with VDRL are the safest and more reliable tests to rule out syphilis from blood donors, since they gave in parallel reliable results to assure the quality of blood to be transfused