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The barrier filter used to date to photograph fingerprints by laser does not eliminate substrate luminescence that can reduce or destroy the value of the fingerprint. Use of a narrow-band-pass filter with an appropriate transmission spectrum can often isolate the desirable fingerprint luminescence and yield a better photograph of the print.
Different countries have different norms with regards to the number of minutiae, which are considered necessary for identification in fingerprint comparison. We investigated these numbers of minutiae with respect to finger, pattern and hand in a sample of 100 Dutch males. The minutiae were counted in the 16 cells of a 20 x 20 mm grid placed on the fingerprint. Statistical analysis showed that individual-, pattern- and fingerfactors, determine the number of minutiae. In this quantitative respect the fingers of both hands can be grouped in two groups: (1, 4) and (2, 3, 5). Because an identification based on a fingerprint, depends on the expected number of minutiae, this study draws special attention on the variation in this number. It is probable that the number of minutiae needed for the identification depends in a greater of lesser degree on finger, pattern, sex and population-group of the individual.
DNA typing of the ABO blood groups from single fingerprints was examined. Genomic DNAs were extracted from fingerprints on slide glasses by a simple method with NaI and N-lauroyl-sarcocinate, and then subjected to the PCR (Polymerase chain reaction). Two PCR fragments spanning positions 258 and 700 of the cDNA sequence of the ABO locus were amplified. Then, the PCR products were digested with a restriction enzyme, Kpn-1 or Msp-1, for each site. The digested PCR products were analyzed by electrophoresis on polyacrylamide gels for RFLP (Restriction-fragment length polymorphism). Bands on the gel were visualized by silver staining. Genotyping from single fingerprints after treatment with aluminium powder was also possible by these techniques.
The effects of time and detonation on latent fingerprints from cartridges and cartridge castings were explored. Time alone did not appear to seriously degrade latent fingerprint quality over the three-week period of experimental trials. The greatest effect of detonation seemed to stem from hot gaseous blowback on the external surface of the cartridge casings. Nickel-plated casings, because of their greater chemical resistance and more polished surface, were found less satisfactory as a substrate for latent impressions than brass casings. An interesting technique for development and permanent preservation of latent fingerprint impressions on castridge casings was also described.
BACKGROUND: A flow cytometric measurement (FCM) technique has been developed to size DNA fragments. Individual fragments of a restriction digest of genomic DNA, stained with an intercalating dye, are passed through an ultrasensitive cytometer. The measured fluorescence intensity from each fragment is proportional to the fragment length. METHODS: The isolation of bacterial genomic DNA and digestion by restriction enzymes were performed inside an agarose plug. Rare cutting enzymes were employed to produce a manageable number of DNA fragments. Electroelution was used to move the DNA fragments from the agarose plug into a solution containing polyamines to protect the DNA from shear-induced breakage. The DNA was stained with the bisintercalating dye thiazole orange homodimer and introduced into our ultrasensitive flow cytometer. A histogram of the fluorescence intensities (fingerprint) was constructed. RESULTS: Gram-positive Bacillus globigii and gram-negative bacteria Escherichia coli and Erwinia herbicola were distinguished by the fingerprint pattern of restriction fragments of their genomic DNA. DNA sizes determined by FCM are in good agreement with pulsed-field gel electrophoresis (PFGE) analysis. Flow cytometry requires only picogram quantities of purified DNA and takes less than 10 min for data collection and analysis. When the total sample preparation time is included, the analysis times for PFGE and FCM are similar ( approximately 3 days). CONCLUSIONS: FCM is an attractive technique for the identification of bacterial species. It is more sensitive and potentially much faster than PFGE.
Here we describe a method for fingerprinting the mouse immunoglobulin heavy chain variable region (VH) repertoire. Using a novel combination of existing techniques, large numbers of expressed VH genes can be simultaneously displayed as a fingerprint of VH gene fragments on a sequencing gel. This is achieved using isotype-specific reverse transcription-PCR amplification, restriction digestion and end-labeled primer run-offs. This technique (Res-PCR) allows analysis of the immune response, in this case to phenyloxazolone, in several different tissues and enables molecular cloning and sequencing of the VH genes involved in vivo. In addition, with Res-PCR, a "global" picture of expressed immunoglobulin genes is represented. This elucidates B cell clonality in different tissues and isotypes and detects a preference for shorter complementarity-determining region 3 in IgM-expressing cells. Res-PCR is a rapid and revealing method which will allow analysis of the complexity and sequence composition of the B cell immunoglobulin repertoire and so perhaps better define the B cell memory compartment and immune responses in vivo.
A total of 356 clinical isolates of the encapsulated basidiomycetous fungus Cryptococcus neoformans var. neoformans, obtained from Australia, Argentina, Brazil, India, Italy, New Zealand, Papua New Guinea, South Africa, Thailand and the USA, were analyzed to lay the basis for a comprehensive evaluation of the global genetic structure of C. neoformans. Two polymerase chain reaction (PCR)-based typing techniques were standardized: PCR fingerprinting using a single primer specific to minisatellite or microsatellite DNA, and randomly amplified polymorphic DNA (RAPD) analysis using two combinations of three 20- to 22-mer random primers. Previous studies showed that the resultant profiles are reproducible and stable over time. Identical results were obtained in two different laboratories and by different scientists in the same laboratory. Both typing techniques separated the isolates into four major groups (VNI and VNII, serotype A; VNIII, serotype A/D; and VNIV, serotype D). The majority (78%) of isolates belonged to VNI, compared with 18% VNII, 1% VNIII and 3% VNIV. All US isolates could be differentiated by a unique, strain-specific PCR fingerprint or RAPD pattern in contrast to most of the non-US isolates, which showed a substantially higher degree of genetic homogeneity, with some clonality, in different parts of the world. Isolates obtained from the same patient at different times and from different body sites, had identical banding patterns. Both typing techniques should provide powerful tools for epidemiological studies of medically important fungi.
DNA typing is a useful tool in crime solving, not only for blood samples, sperm, or saliva but also for traces of DNA left on tools or pieces of clothing used in burglaries or thefts. On these kinds of samples, the sources of DNA are extremely small amounts of skin debris left after gripping tools. When a sensitive technique such as polymerase chain reaction (PCR) coupled with capillary electrophoresis is used, it is possible to get a profile from these low amounts of DNA. The classic technique in such cases, used in forensic sciences, is to reveal fingerprints by different dactyloscopic powders. Therefore, DNA profiling was performed on physical fingerprints left on glass and wooden plates, in order to establish eventual problems or interferences involved by using both techniques simultaneously. Eleven dactyloscopic powders were investigated on their influence on DNA typing. The results show that some can be used together with DNA profiling but that serious precautions have to be taken to avoid contamination.
The power of multilocus DNA fingerprinting depends on the reliability with which the uniqueness of an individual's profile can be demonstrated. This cautionary note stresses the importance of the probe concentration in this procedure. In case of a probe shortage, DNA fragments rich in tandem repeats have the potential to impede hybridization in other parts of the gel, and thus interfere with bands that are part of a DNA fingerprinting profile.
Polymerase chain reation (PCR) fingerprints are used to characterize and recognize bacteria and are generally obtained using universal primers that generate an array of DNA amplicons, which can be separated by electrophoresis. Universal primers 8F and 1491 R have been used to amplify specifically 16S rDNA. We have used these primers at an annealing temperature of 50 degrees C. Agarose gel electrophoresis of PCR products revealed several bands. The band pattern of each bacterial species was different and the strains belonging to the same species shared an identical pattern. The patterns obtained did not show variations with plasmid DNA content or the growth stage of the bacteria. The peculiarity of the randomly amplified polymorphic DNA (RAPD) described in this work lies in the use of two large primers (proximately 20 nt) to obtain the pattern, since normally a only smaller primer is used, and in the new application for the primers used to amplify 16S rDNA. This new procedure, called two primers (TP)-RAPD fingerprinting, is thus rapid, sensitive, reliable, highly reproducible and suitable for experiments with a large number of microorganisms, and can be applied to bacterial taxonomy, ecological studies and for the detection of new bacterial species.
Simple sequences are short regions of tandem repetitions of mono-, di-, tri-, or tetranucleotide motifs and occur as repetitive elements in all eukaryotic genomes. These regions tend to be hypervariable in length and can therefore be exploited for DNA fingerprinting purposes, using the polymerase chain reaction with primers flanking such regions. We describe how suitable simple-sequence loci can be isolated from any given eukaryotic DNA. We show the DNA sequences for a number of variants of such loci and discuss the current results on their usefulness for DNA fingerprinting.
DNAs of several species of domestic animals digested with the restriction endonucleases HinfI, AluI and HaeIII were hybridized with different synthetic probes. DNA fingerprint patterns were found in each investigated species by at least two of these probes. Furthermore, two probes gave sex-specific banding patterns in the chicken. Some applications of DNA fingerprinting in domestic animals are discussed.
We replicated DNA fingerprints of snapping turtles (Chelydra serpentina) and hypervariable restriction fragments of red-winged blackbirds (Agelaius phoeniceus) to estimate the between-blot and between-lane components of variance in molecular weights of restriction fragments. Molecular weight standards were included in every lane, and bands were sized using a sonic digitizer. In both studies, a strong positive correlation was found between band size and coefficient of variation (CV; mean = 0.7%). In the DNA fingerprint study, 26% of the variance in estimates of band size was due to differences between blots, 10% due to differences between lanes on the same blot, and 64% due to error in the digitizing process. In the restriction fragment length polymorphism (RFLP) study, 16% of the variance was due to difference between lanes, and 84% to digitizing. Statistical models were developed to measure the effect of sizing error on identifying identical fragments in different lanes or on different blots, in categorizing distinct alleles, and in determining the size of bins in operational allele definitions. We suggest that the distance between bands be at least 2.8 standard deviations (SD) before they are declared different at alpha = 0.05, and 3.7 SD for alpha = 0.01. A variation in CVs strongly indicates that empirical relationships between SD and band size must be used to decide if two bands represent the same allele. Alleles must be at least 3.9 SD apart before the chance of assigning new observations in error falls below 0.05. We suggest that a minimum bin width of 16 SD is necessary before the chances of assigning a band to the wrong bin falls below 0.05.
A novel concept is described for the statistical analysis of multilocus DNA fingerprints. Utilizing this method, it is shown by simulation that the application of multilocus DNA fingerprints to paternity testing is robust against deviations from idealistic assumptions made about underlying models and parameters. Partial homozygosity, allelism and linkage at the DNA loci involved, as well as variations in estimates of band-sharing probabilities were studied for effects on the resulting paternity probabilities. None of the above-mentioned phenomena appear to change these values to an extent relevant for decision making in paternity cases.
To investigate genetic heterogeneity during in vitro cultivation of human prostatic carcinomas following radical prostatectomy we performed DNA fingerprinting using the digoxygenin-labeled probes (GACA)4 and (GTG)5. DNA was isolated from fresh material stemming from different areas within one tumor and from cell cultures of the same material. The patterns which were obtained by the nucleolar organizer region (NOR)-specific probe (GACA)4 exhibit only a few prominent low molecular mass bands and no differences were observed between any of the tumors analyzed so far. Changes in the fingerprint pattern occurred between cell cultures derived from different areas within one tumor when the DNA was cleaved by HaeIII and signals detected with the (GTG)5 probe. The "area-specific" pattern was stable during several subcultivations of these cell lines, indicating genetic stability of these prostatic carcinoma cells in vitro. Thus individual cell lines derived from radical prostatectomy seem to represent a biological system very close to the situation in vivo.
Digoxigenated oligonucleotide probes complementary to simple repetitive DNA sequences were introduced into nonradioactive fingerprint analysis of plant and fungal DNA. The fragment patterns, obtained by blot hybridization of TaqI-restricted DNA from chickpea (Cicer arietinum) and its fungal pathogen Ascochyta rabiei with digoxigenated probes and either a colorigenic or a chemiluminescent detection method, were compared to those obtained with 32P-labeled probes. In combination with alkaline phosphatase and its chemiluminescent substrate 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl- 1,2-dioxetane (AMPPD) digoxigenated oligonucleotides yielded clear-cut fingerprints with high signal-to-background ratios within several minutes of exposure to X-ray films. The chemiluminescence reaction remained stable for at least two weeks. A comparison of banding patterns obtained by radioactive versus digoxigenin-based hybridization and detection techniques revealed substantial differences in the relative signal intensities of bands. Both nonradioactive techniques show a tendency to "equalize" band intensity differences. Whereas 32P-labeled oligonucleotides are also applicable to in situ hybridization with DNA immobilized in dried agarose gels, gel hybridization did not work efficiently with digoxigenated probes and either substrate.
A simulation study was performed in order to determine whether or not the assumption of independence, made in the quantitative analysis of multilocus DNA fingerprints, represents an inadmissible over-simplification. A total of 10,000 cases of true and false paternity, respectively, were simulated in twenty replicas of various genetic models. Log-likelihood ratios (paternity vs. non-paternity; LR) were calculated using published likelihood formulae and assuming position-wise independence. The resulting LR distributions were compared to (i) the results of a classical analysis of the underlying genotype data, and (ii) the distributions expected from the likelihood model employed in the LR calculations. Although considerable discrepancies were observed between these distributions, decision making about paternity appeared to be only marginally affected, especially when only a fraction of each multilocus DNA fingerprint was analyzed.
A novel version of the polymerase chain reaction (PCR) termed degenerate oligonucleotide-primed PCR (DOP-PCR) was used to fingerprint the bacterial genome of Yersinia enterocolitica species. Eight well-characterized reference strains of Y. enterocolitica (ribotype, serotype, biotype and zymotype) were examined. Optimal experimental conditions for reproducibility, sensitivity and specificity were obtained using a single DOP-primer. All the strains gave distinct DOP-PCR profiles composed of 12 to 19 fragments with sizes from 200 to 1.500 bp. Thus, the DOP-PCR, which has so far been used to fingerprint human, mouse, fruitfly and plant DNA, is also well-suited to bacterial DNA.