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1.
Simple and rapid detection of HLA-DRB polymorphism has been performed using AMPLICOR HLA-DRB Typing Kit. We tried to apply this kit to various forensic samples. When DNA was extracted from the forensic samples using conventional phenol-chloroform method, addition of 7.5 mM MgCl2 was required to PCR amplification. HLA-DRB types were detected from DNA more than 0.1 ng by PCR amplification. Typing of unrelated 50 Japanese showed 38 different patterns, of which 30 patterns occurred once in the group. A total of 16 serotypes were deduced from the HLA-DRB DNA types. Out of them, high frequency serotypes were DR4 (24%), DR9 (18%) and DR15/16 (14%). This kit was very useful in forensic cases such as rape and in paternity cases. When we tried to detect HLA-DRB types from a single hair shaft of 3 cm in length, we were successful in detection from only one of five persons.  相似文献   

2.
Applied DNA typing in medico-legal investigations, in criminalistic practice, and in paternity cases often relies on high inclusion and exclusion probabilities. For that reason, the short autosomal tandem repeat locus D8D306 was validated for forensic use and incorporated into a nonoverlapping multiplex reaction with HUMDHFRP2 and HUMCD4: The allele frequencies of D8S306 in four different regions of Germany (n = 1220 alleles) were determined for use in a population database; the allele distributions did not significantly deviate from each other. The hererozygosity of D8S306 is 83%, expected exclusion chance in stain cases is 96% (paternity cases: 69%), the lowest amount of successfully amplified DNA was 30 pg. The alleles are in Hardy-Weinberg equilibrium.  相似文献   

3.
The use of DNA typing in human genome analysis is increasing and finding widespread application in the area of forensic and paternity testing. In this report, we explore the feasibility of typing single nucleotide polymorphisms (SNPs) by using a semiautomated method for analyzing human DNA samples. In this approach, PCR is used to amplify segments of human DNA containing a common SNP. Allelic nucleotides in the amplified product are then typed by a colorimetric implementation of the oligonucleotide ligation assay (OLA). The results of the combined assay, PCR/OLA, are read directly by a spectrophotometer; the absorbances are compiled; and the genotypes are automatically determined. A panel of 20 markers has been developed for DNA typing and has been tested using a sample panel from the CEPH pedigrees (CEPH parents). The results of this typing, as well as the potential to apply this method to larger populations, are discussed.  相似文献   

4.
Definitive diagnosis of Onchocerca volvulus (Ov) infection requires the identification of the parasite in either the skin or subcutaneous nodules. These parasitologic approaches suffer from poor sensitivity. To assess the efficacy and utility of a polymerase chain reaction (PCR)-based diagnosis for Ov infection, skin snips were examined from 94 persons in an Ov-endemic region of Ecuador, and results were compared in a blinded fashion with those of a PCR assay based on the Onchocerca-specific repetitive DNA sequence, O-150. All 60 patients microfilaria-positive on skin snip examination were positive in the PCR-based assay. In addition, 13 of 34 who were microfilaria-negative by skin snips were positive in the PCR assay. This suggests that the PCR-based assay is significantly more sensitive than current methods and overcomes many deficiencies of parasitologic and serologic methodologies in diagnosing active onchocerciasis.  相似文献   

5.
Alu sequences are present in humans in excess of 500,000 copies per haploid genome and represent the largest family of short interspersed repetitive elements (SINEs). These mobile genetic elements are ancestrally derived from the 7SL RNA gene and move throughout the genomes of primates by retroposition. Polymorphic Alu insertions have proven to be useful for population studies, paternity determinations and forensic applications. Additionally, a simple polymerase chain reaction (PCR)-based assay has been established to examine these polymorphisms. In the present study, we have applied the technique of multiplex polymerase chain reaction to the Alu polymorphic system. Duplex and triplex PCR reactions were performed for the analysis of five different Alu polymorphic loci in different combinations. This study represents a starting point for further experimentation to improve and eventually optimize Alu multiplex PCR.  相似文献   

6.
DNA has been previously recovered from human teeth for RFLP and PCR-based forensic analysis. In some cases, the maximum amount of undisturbed tooth structure is required for ulterior forensic analysis. But, in most cases, following comprehensive documentation, it is possible to section the tooth longitudinally or horizontally, or crush it to access the DNA-rich core. This technical report describes an alternative method to recover DNA from whole extracted human molar teeth. A 6700 freezer mill was used to pulverize 20 teeth under frozen preparation in liquid nitrogen and sterile conditions. The mean yield of DNA was 30.9 micrograms (18.4 micrograms DNA per gm tooth powder). The resulting fine powder was subjected to organic extraction and subsequently quantified using slot blot hybridization. Aliquots were successfully amplified at three short tandem repeat polymorphic loci. The technique is simple and relatively rapid. Isolation of the samples during pulverization minimizes the risk of contamination.  相似文献   

7.
Frequency data for the STR system HumFGA were obtained from a North Italian population sample (Milano area) of 201 unrelated individuals. PCR products were detected by horizontal polyacrylamide gel electrophoresis and a total of 15 alleles were identified by side-by-side comparison with a commercially available sequenced allelic ladder. The observed genotype distribution showed no significant deviation from Hardy-Weinberg equilibrium. The high information content (discrimination power > 0.96, polymorphism information content > 0.84) render this system a useful tool in forensic routine casework both in criminal and paternity cases.  相似文献   

8.
The detection of restriction fragment length polymorphisms (RFLP) (1) in DNA extracted from forensic samples remains impossible in a significant number of cases due to deterioration and contamination of the biological material and the extremely low quantities of DNA isolated. The polymerase chain reaction (PCR) is a recent and particularly convenient method for analysing and typing very small amounts (10-20 ng) of degraded human DNA. DNA analysis at the level of a few cells present in forensic samples such as bloodstains, semen stains, vaginal swabs and head hair bulbs now appears possible using DNA amplification. A PCR protocol was adapted to simultaneously amplify a Y-specific DNA repeat sequence from the DYZ1 locus and an X-specific DNA repeat sequence from the DXS424 locus. The co-amplified Y-specific DNA fragment (102 bp) and X-specific DNA fragments (181-199 bp) were visualized on an ethidium bromide-stained 4% agarose gel. The male or female type of the amplified DNA extracted from blood samples, bloodstains, semen stains, vaginal swabs, brain tissue and 1, 2, 5, or 10 head hair bulbs was determined.  相似文献   

9.
OBJECTIVE: This study aimed to review the authors' results using polymerase chain reaction (PCR)-based assays for the diagnosis of viral retinitis. DESIGN: The study design was a retrospective case series. PARTICIPANTS: Thirty-seven patients (38 eyes) with active retinitis from whom vitreous biopsy specimens were received in the authors' laboratory for diagnostic evaluation. INTERVENTION: Vitreous biopsy specimens were evaluated with previously described PCR-based assays for cytomegalovirus (CMV), varicella zoster virus (VZV), and herpes simplex virus (HSV) DNA; clinical histories were reviewed. MAIN OUTCOME MEASURES: Laboratory findings and clinical course were measured. RESULTS: The results of the authors' assays were consistent with the long-term clinical course of each patient. Cytomegalovirus, VZV, or HSV DNA was detected in the vitreous from 24 patients. Cytomegalovirus DNA was detected in vitreous biopsy specimens from 10 patients (11 eyes). Nine patients (ten eyes) with acquired immune deficiency syndrome ultimately were diagnosed with CMV retinitis as they were followed clinically over time. Varicella zoster virus DNA was detected in vitreous biopsy specimens from eight patients; seven adult patients were ultimately diagnosed with acute retinal necrosis or progressive outer retinal necrosis. Herpes simplex virus DNA was detected in vitreous biopsy specimens from six patients; five patients had previous or subsequent herpes encephalitis. No viral DNA was detected in the vitreous from 13 patients; all were ultimately diagnosed with toxoplasmosis, syphilis, Behcet disease, fungal endophthalmitis, or idiopathic inflammation. CONCLUSIONS: These data further support the use of PCR-based assays of vitreous specimens in the diagnostic evaluation of patients with infectious retinitis.  相似文献   

10.
Primer extension preamplification (PEP), which can amplify sequence-independently a limited quantity of DNA as a whole, allows multiple DNA analyses by polymerase chain reaction (PCR). This technique may be applicable to forensic cases, especially in cases where only small amounts of DNA are available. To define the accuracy and sensitivity of PEP, the DNA typing results of nine loci (TH01, MCT118, HLA-DQ alpha, amelogenin, LDLR, GYPA, HBGG, D7S8, GC) by PCR with PEP (PEP-PCR) were compared with those by PCR without PEP. Both results were identical to each other for each sample tested. Furthermore, amplification of an initial genomic DNA by PEP was found to range from 15 to 600 times of the initial quantity and the efficiency of PEP may depend on the sequences flanking the loci tested. These results indicate that PEP can increase typing potential of PCR from forensic samples.  相似文献   

11.
A nested polymerase chain reaction (PCR)-based assay, for detection of bluetongue virus (BTV) ribonucleic acid in cell culture and tissue samples, was developed. Two pairs of oligonucleotide primers (BTV1 and BTV4 and BTV2 and BTV3), selected from non-structural protein 1 (NS1) gene of BTV-17, were used for the nested PCR in two amplification steps. First a 826-bp product was amplified using an outer primer pair BTV1 and BTV4. The second amplification, using nested or internal primer pair BTV2 and BTV3, produced a 517-bp PCR product. RNA from North American prototype serotypes 2, 10, 11, 13 and 17, propagated in cell cultures, were detected by this nested PCR-based assay. The nested primers BTV2 and BTV3 increased the sensitivity of the BTV PCR assay, and as little as 0.1 fg of BTV RNA (equivalent to 5 viral particles) could be detected. Amplification products were not detected when the PCR-based assay was applied to RNA from a closely related orbivirus, epizootic hemorrhagic disease virus (EHDV) prototype serotypes 1 and 2; total nucleic acid extracts from uninfected BHK-21 cells; or whole blood from calves and deer that were BTV-seronegative and virus isolation negative. Application of this nested BTV PCR-based assay to clinical samples resulted in detection of BTV RNA from a variety of tissues collected from calves and deer with natural and experimental BTV infections. The described BTV PCR-based assay provides a valuable tool to study the epidemiology of BTV infection in susceptible wild ruminants and domestic livestock.  相似文献   

12.
A multiplex PCR-based assay was developed for the detection of Bordetella pertussis in nasopharyngeal swab specimens. The assay simultaneously amplified two separate DNA targets (153 and 203 bp) within a B. pertussis repetitive element and a 438-bp target within the beta-actin gene of human DNA (PCR amplification control). PCR products were detected by a sensitive and specific liquid hybridization gel retardation assay. A total of 496 paired nasopharyngeal swab specimens were tested by both the PCR-based assay and culture. Although 30 (6%) of the specimens inhibited the amplification of the beta-actin target, in all 29 specimens studied, the inhibition disappeared on repeat testing or was easily overcome with a 1:8 dilution or less of specimen digest. Of the 495 specimen pairs yielding a final evaluable result by the PCR-based assay, 19.0% were positive by the PCR-based assay, whereas 13.9% were positive by culture (P < 0.0001). After resolving the PCR-positive, culture-negative results by testing an additional aliquot from these specimens by the multiplex PCR-based assay, the PCR-based assay had a sensitivity and specificity of 98.9 and 99.7%, respectively, compared with values of 73.4 and 100%, respectively, for culture. In comparison with patients with culture-confirmed pertussis, those with PCR-positive, culture-negative results were older and more likely to have had prolonged cough, immunization with pertussis vaccine, or treatment with erythromycin. This multiplex PCR-based assay is substantially more sensitive than culture and identifies specimens that contain inhibitors of PCR.  相似文献   

13.
Extraction of DNA from old skeletal material is of great importance in the identification of human remains, but is particularly difficult because the methods currently employed, especially those using phenol/chloroform, are not always satisfactory. A simple technique based on the removal of non-nucleic acid material by salting out (precipitation) with saturated sodium acetate is described; the presence of DNA in the extract being confirmed by amplification of selected sequences of the HLA-DRB1 gene using the polymerase chain reaction (PCR). The method was applied to fresh bone (five femoral heads and six vertebral bodies) and to bone from two forensic cases, 3 and 9 months post-mortem, respectively. Parallel extractions using the phenol/chloroform technique were performed on all samples in order to compare the efficiency of the two methods. Using sodium acetate precipitation, amplifiable DNA was consistently extracted from fresh bone, as well as from the two forensic cases. With the phenol/chloroform method, amplification was successful in only 7 out of 11 instances with the fresh bone samples and failed in both forensic cases. The studies also showed that an effective way of removing PCR inhibitors is to subject the extract to agarose gel electrophoresis, isolate the high molecular weight area and re-extract the DNA from the gel by boiling. It was concluded that the sodium acetate method is a valid alternative to established techniques for extracting DNA from bone and that it offers the advantages of being simple, quick, inexpensive and avoids using hazardous reagents.  相似文献   

14.
A polymerase chain reaction (PCR)-based short tandem repeat (STR) system consisting of nine loci has recently been introduced in Slovenia for use in routine forensic identity testing. Fluorescently labelled PCR products were analysed using an ABI PRISM 310 Genetic Analyzer. The STR loci analysed exhibit between 6 and 14 observed alleles per locus and have a combined matching probability of 2.3 x 10(-10).  相似文献   

15.
With the advancement of techniques in molecular biology, rapid, sensitive, and reliable methods of DNA typing for parentage testing have become available. In this study, we evaluated the usefulness of multiplex polymerase chain reaction (PCR) with 12 unlinked short tandem repeat (STR) loci for paternity testing in Taiwan. The genetic informativeness of this test was then compared with that of conventional human leukocyte antigen (HLA) analysis in 167 parentage studies. The 12 STR loci alone provided a cumulative power of exclusion of up to 0.9998. Paternity was excluded in 59 (35.3%) cases, including 40 of 112 paternity trios and 19 of 55 paternity duos. In the 40 trios in which paternity was excluded, a mean of 6 (range, 3-9) incompatible STR markers were in the 19 duos in which paternity was excluded, a mean of 4 (range, 1-8) incompatible STR markers were noted. In the 72 trios in which the alleged paternity could not be excluded, the mean probabilities of paternity (PP) were 90.6863% with HLA testing alone, 99.9847% with STR analysis alone, and 99.9972% with combined HLA and STR analysis. In the 36 duos in which the alleged paternity could not be excluded, the mean PPs were 81.4768% with HLA testing alone, 99.6124% with STR analysis alone, and 99.9145% with combined HLA and STR analysis. These results suggest that STR analysis is very powerful when used alone for paternity trio testing and when combined with conventional serologic HLA typing for duo parentage testing in the Taiwan population.  相似文献   

16.
Polymerase chain reaction (PCR)-based assays were developed to detect virulent Rhodococcus equi in transtracheal aspirate samples from sick foals showing respiratory signs. An oligonucleotide primer pair from the sequence of the virulence-associated 15- to 17-kDa antigen gene of the virulence plasmid in virulent R. equi was used to amplify a 564 bp region by PCR, and the result was confirmed by Southern blot hybridization. No positive reaction was seen in DNA from 13 different microorganisms typically found in the respiratory tract. In tracheal aspirates seeded with virulent R. equi, a visible band could detect 10 to 10(2) bacteria per PCR assay (10(3) to 10(4)/ml of the aspirate). Virulent R. equi was demonstrated in 31 of 42 transtracheal aspirates by culture and colony blot analysis, whereas a positive PCR result was observed in only 12 of the 31 culture positive samples. To prevent false-negative results, two methods were developed: a nested PCR and a PCR in combination with enrichment cultures of aspirates in the selective medium to increase the number of bacteria to 10(4)/ml or more. All of the PCR-negative and culture-positive samples were positive by the two methods. These results indicated that PCR-based assays provide a specific and sensitive means to detect virulent R. equi in tracheal aspirates of foals, and they are more rapid than the routine culture procedures for the diagnosis of R. equi pneumonia in foals.  相似文献   

17.
Characterization of 43 strains of Rhizobium leguminosarum biovars viciae, trifolii, and phaseoli was performed by two methodologies based on PCR amplification, i.e., PCR DNA fingerprinting of interrepeat sequences and restriction fragment length polymorphism (RFLP) analysis of PCR -amplified chromosomal and symbiotic gene regions. Groupings generated by PCR DNA fingerprinting with either extragenic palindromic repetitive primers or two different single random primers were correlated with similar levels of resolution. Although less discriminating, PCR-RFLP analysis of intergenic spacer between genes coding for 16S and 23S rRNA (16S and 23S rDNA) yielded intraspecific polymorphisms. The classification of strains was independent of the biovar status and was in agreement with those obtained by PCR DNA fingerprinting. Intrabiovar variation within symbiotic gene regions was detected by PCR-RFLP analysis of nifDK and nodD gene regions, but the strains were grouped according to the biovar. The rDNA intergenic spacer and nif primers were verified to be universal for rhizobial species by testing of various reference strains, whereas the nod primers designed in this study were biovar or species specific for R. leguminosarum and Rhizobium etli. Classifications of R. leguminosarum strains by the PCR-based methods were correlated with those previously obtained by conventional total DNA restriction profile comparisons and RFLP analysis using chromosomal and symbiotic gene probes. Ranges of discriminating powers were also equivalent between the two approaches. However, the PCR-based methods are much less time-consuming and are therefore more convenient.  相似文献   

18.
In a forensic case of disputed paternity an apparent mother/child incompatibility with respect to red cell acid phosphatase was found, the mother appearing as type A and the child as type B. Determination of electrophoretic type and of acid phosphatase activity in 8 of the family members strongly suggested the presence of a silent gene PO in 4 of the individuals. The phosphatase levels in the four heterozygotes were about half the values expected from normal values determined in 100 healthy adults representing the different phenotypes. The distribution of red cell acid phosphatase types in 3,735 unrelated Danish adults and in 1,109 mother/child pairs is reported; gene frequencies Pa = 0.369, Pb = 0.566 and Pc = 0.065. The PO gene frequency was roughly estimated as 0.001. Results are reported on the application of the red cell acid phosphatase system to 300 2-men cases of disputed paternity.  相似文献   

19.
Multiplex PCR amplification has been useful for gene mapping with polymorphic short tandem repeat (STR) loci. We have tested the four loci D20S470, D13S325, HumFOLP23 and D10S2325 for the simultaneous typing of more than 100 unrelated Koreans. This analysis allows a single base pair resolution and rapid typing with silver staining. The allele and genotype distributions are in accordance with Hardy - Weinberg expectations. These STR loci have proven useful for forensic analysis and paternity tests in which the variable number of tandem repeat (VNTR) loci have some limitations.  相似文献   

20.
We have investigated the role of two rapid PCR-based typing methods, IS6110-based PCR and spacer-oligonucleotide typing, within a national tuberculosis reference service. The validity of clusters with IS6110 restriction fragment length polymorphism fingerprints with less than 6 bands was also investigated in the context of referred isolates.  相似文献   

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