scholarly journals Modified Method to Detect PCR Products by 5′Nuclease Activity and an Asymmetric Fluorogenic Probe Set

BioTechniques ◽  
2000 ◽  
Vol 29 (4) ◽  
pp. 690-694 ◽  
Author(s):  
Kai Koo ◽  
Lee-Ann Jaykus
1999 ◽  
Vol 62 (4) ◽  
pp. 329-335 ◽  
Author(s):  
BON KIMURA ◽  
SUSUMU KAWASAKI ◽  
TATEO FUJII ◽  
JUN KUSUNOKI ◽  
TAKESHI ITOH ◽  
...  

We evaluated the TaqMan Salmonella amplification/detection kit from PE Applied Biosystems, which uses a polymerase chain reaction (PCR) assay for rapid detection of Salmonella in food samples. This system uses the 5′ nuclease activity of Taq DNA polymerase, which digests an internal fluorogenic probe to monitor the amplification of the target gene. The system's sensitivity and specificity were evaluated using 42 serotypes of 68 Salmonella strains isolated from fecal samples from patients in Tokyo, Japan, and 39 non-Salmonella strains in 22 genera. There were no false-negative or false-positive results. This PCR assay can detect 3 CFU per PCR tube of Salmonella in pure culture (120 CFU/ml of TSB culture). PCR signals were attenuated with artificially contaminated shrimp, but a similar detection limit was obtained. TaqMan's performance was tested with 100 meat and chicken samples purchased from stores in Tokyo. Overall, two of the DNA extraction protocols (the Chelex and EnviroAmp methods) worked equally well, with some exceptions. Of the 100 samples analyzed, 10 were positive for Salmonella with both conventional culture methods and the kit and 89 were negative with both. One sample was negative by the culture method but positive by the kit assay. These results indicate that TaqMan is a reliable and rapid method for Salmonella analysis in the food industry. With this system, food samples can be analyzed for Salmonella in less than 20 h.


1995 ◽  
Vol 73 (05) ◽  
pp. 756-762 ◽  
Author(s):  
Yoshiaki Tomiyama ◽  
Hirokazu Kashiwagi ◽  
Satoru Kosugi ◽  
Masamichi Shiraga ◽  
Yoshio Kanayama ◽  
...  

SummaryWe analyzed the molecular genetic defect responsible for type I Glanzmann’s thrombasthenia in a Japanese patient. In an immunoblot assay using polyclonal anti-GPIIb-IIIa antibodies, some GPIIIa (15% of normal amount) could be detected in the patient’s platelets, whereas GPIIb could not (<2% of normal amount). Nucleotide sequence analysis of platelet GPIIb mRNA-derived polymerase chain reaction (PCR) products revealed that patient’s GPIIb cDNA had a 75-bp deletion in the 3’ boundary of exon 17 resulting in an in-frame deletion of 25 amino acids. DNA analysis and family study revealed that the patient was a compound heterozygote of two GPIIb gene defects. One allele derived from her father was not expressed in platelets, and the other allele derived from her mother had a 9644C → T mutation which was located at the position -3 of the splice donor junction of exon 17 and resulted in a termination codon (TGA). Moreover, quantitative analysis demonstrated that the amount of the abnormal GPIIb transcript in the patient’s platelets was markedly reduced. Thus, the C → T mutation resulting in the abnormal splicing of GPIIb transcript and the reduction in its amount is responsible for Glanzmann’s thrombasthenia.


1997 ◽  
Vol 78 (05) ◽  
pp. 1360-1365 ◽  
Author(s):  
G Freyburger ◽  
S Javorschi ◽  
S Labrouche ◽  
P Bernard

SummaryThe aim of the present study was to evaluate the relative performance of five screening methods for APC resistance caused by the factor V:Q506 mutation: the original method Coatest® APC™ Resistance Chromogenix, a modified method using the same reagents but a predilution 1+4 of the plasma in a factor V deficient plasma from Stago (Stago deficient V) or from Chromogenix (V-DEF Plasma), the Coatest® APC™ Resistance V (Chromogenix), and Accelerimat™ from bioMérieux. Normalization was done against a pool of normal plasmas for the methods from Chromogenix. The study included 350 subjects, 219 were genotyped (174 FV:R506R, 42 FV:Q506R, 3 FV:Q506Q) and most of them were assessed by more than one method. Uncertainty in predicting the FV genotype was evaluated by statistical analysis, which provided a way to quantitate the performance of the different diagnostic approaches. Performance of each test was evaluated by its sensitivity, specificity, R.O.C. curves, positive and negative likelihood ratios (LR), and the overall performance was determined by two parameters derived from the LR curves : the maximum LR value obtained at the crossover of the two curves, and the distance between the two curves for LR = 10. Coatest® APC™ Resistance V and Accelerimat™ were proven to be the methods most able to discriminate for factor V:Q506, while normalization was not shown to improve the screening performance. The original method from Chromogenix was confirmed to undergo many influences (factor XII, PAI-1, thrombin- antithrombin complexes, antithrombin III, hematocrit). Although a very good improvement was provided by the newest methods, they were shown to be influenced by protein S and/or factor V levels in the sample plasma.


2020 ◽  
pp. 132-139

In this study, only (122) out of (915) primary school students were shown to be infected with head lice Pediculus. humanus capitis. The number and percentage of infected males were 46 (11.3%), while the number and percentage of infected females were 76 (14.9%). The results in our study also showed that the number and percentage of goats infected with goat sucking lice, Linognathus stenopsis was 70 (21.7%) of the total 322 animals, with the highest number and percentage among female goats 44 (62.9%) compared to the male goats 26 (37.1%). The study demonstrated that the rate of genetic difference between the studied samples was 89% and the similarity rate was 11%. Detection of OP-K01 gene pieces by PCR products showed that the amplicon size was 520 bp for P. humanus capitis isolated from humans, while the detection of OP-E20 and OP-M05 gene pieces with PCR product showed the lowest amplicon size 230 bp for Linognathus stenosis isolated from goats.


1969 ◽  
Vol 60 (4) ◽  
pp. 657-668 ◽  
Author(s):  
Frances J. Thomas ◽  
A. W. Steinbeck

ABSTRACT A modified method for the estimation of urinary pregnanetriol, pregnanetriol, pregnanetriolone, Δ5-pregnenetriol and tetrahydro S was investigated. The steroids, separated by chromatography, were measured quantitatively, tetrahydro S by reaction with blue tetrazolium and the other three as acetaldehydogenic substances. The excretion of these steroids was studied in suspected instances of adrenal and/or ovarian disease. Urinary pregnanetriol and tetrahydro S levels were normal in Cushing's syndrome, secondary adrenocortical carcinoma, the Stein-Leventhal syndrome, idiopathic hirsutism and hypertension. Tetrahydro S was doubtfully elevated in an instance of ectopic ACTH Cushing's syndrome. Pregnanetriol excretion was elevated in untreated cases of congenital adrenal hyperplasia and after treatment in some. Pregnanetriolone was found in all patients with congenital adrenal hyperplasia, including those receiving cortisone. Pregnanetriolone was also detected in Cushing's syndrome, secondary adrenocortical carcinoma, the Stein-Leventhal syndrome, ectopic ACTH Cushing's syndrome and suspected congenital adrenal hyperplasia. Δ5-pregnenetriol was present as a glucuronide in the Stein-Leventhal syndrome and idiopathic hirsutism. The diagnostic implications of these results are discussed.


2012 ◽  
Vol 17 (4) ◽  
pp. 45-50
Author(s):  
Zbigniew Bubliński ◽  
Piotr Pawlik

Abstract The paper presents the modification of background generation algorithm based on analysis of the frequency of occurrences of pixels. The proposed solution allows the generation of the background and its updating, the introduced parameter allows to adjust the algorithm according to the time rate of changes in the image. The results show that the modified method can be applied in many tasks related to the detection and analysis of moving objects.


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