Studied by 1 personForensic serology
is the component of forensic biology that deals with the examination and identification of biological evidence.
Short Tandem Repeats (STR)
The most commonly utilized forensic DNA analysis used for human identification.
Y-chromosomal STR analysis
is often utilized for the investigation of sexual assault crimes.
Mitochondrial DNA analysis
is used for the identification of human remains.
presumptive and confirmatory assays
The identification of bodily fluids can be carried out using ______ to identify the type of bodily fluid in question.
Positive assay
indicates the possibility of the presence of the bodily fluid in question.
Negative assay
indicates that the questioned bodily fluid is absent.
Confirmatory Assays
These assays are utilized to identify bodily fluids with higher certainty than presumptive assays.
Primary Binding Assays
It involves the initial binding between a single epitope of an antigen and a single binding site of an antibody. They are very sensitive.
Secondary Binding Assays
They are less sensitive and easier to perform than primary binding assays.
Precipitation-based assays
________ have been used for species identification.
Agglutination-based assays
______ are more sensitive. It detects antigens located on the surface of cells or carriers, are normally applied to blood group typing.
Enzyme-Linked Immunosorbent Assay (ELISA)
It is an immuno-enzyme assay that can be used to detect and measure the antibody or antigen in question.
Antibody-sandwich ELISA
The most common ELISA that is used in forensic serology.
Immunodiffusion
A passive method in which an antigen or an antibody or both are allowed to diffuse and therefore a gradient, from low to high concentration, is established for an antigen or an antibody or both.
Single Immunodiffusion
A concentration gradient is established for either an antigen or an antibody.
Double Immunodiffusion
A concentration gradient is established for both an antigen and an antibody.
Immunoelectrophoresis (IEP)
This technique uses electrophoresis to separate the antigen mixture prior to immunodiffusion.
Crossed Immunoelectrophoresis
Also known as two-dimensional IEP, is a modification of IEP.
Rocket Immunoelectrophoresis
An antibody-containing agarose gel is used. The antigen is loaded into the well.
Crossed-Over Immunoelectrophoresis
This technique is also known as counterimmunoelectrophoresis (CIE).
Agglutination reactions
can be used as forensic serological assays such as for blood group typing and menstrual blood identification.
Agglutination assays
are qualitative, indicating the absence or presence of antigens or antibodies.
Semi-quantitative assays
results can be obtained by titration.
Direct agglutination assays
involve reactions in which an antibody interacts with antigens originally located on cell surfaces.
hemagglutination reaction
In a ______, an antibody binds to the antigens located on erythrocytes.
Agglutination inhibition assays
The presence of an antigen in question is indirectly detected.
Passive agglutination assays
The antigen is coated on the surface of carrier cells such as tannic acid–treated sheep erythrocytes.
CpG dinucleotide sequences
In the eukaryotic genome, methylation occurs at the cytosine residues commonly in the _________ of both DNA strands.
phosphodiester
The “p” in CpG refers to the _______ bond between cytosine and guanine.
Cytosine methylation
is carried out in vivo by methyltransferase.
Genomic Loci
Also known as tissue-specific differentially methylated regions (TDMRs).
Methylation-sensitive restriction enzyme digestion polymerase chain reaction (MSRE-PCR)
can be used for the rapid detection of DNA methylation.
Bisulfite sequencing
The genomic DNA is treated with sodium bisulfite, which catalyzes the hydrolytic deamination of unmethylated cytosines.
Methyl-DNA immunoprecipitation (MeDIP)
is a useful method for isolating methylated DNA.
Messenger RNA-Based Assays
can potentially be used for wound age estimation and the age of biological stains.
Reference genes
Are constitutively expressed housekeeping genes are utilized as internal controls.
MicroRNA-Based Assays
The biological function of microRNAs (miRNAs) is to regulate gene expression.
Mass spectrometry (MS)
is a susceptible and rapid technique for protein identification from complex biological samples.
Mass spectrometer
An analytical technique to identify a molecule by measuring the ratio of the mass (m) to the charge (z) of a charged molecule.
Ion source
Converts analytes into gaseous phase ions through ionization.
Ionization
A process used by gaining a positive or a negative charge from a neutral species.
Mass Analyzer
A part of a mass spectrometer where ions are accelerated under electric fields and separated based on their m/z ratio.
Biomarker proteins
can be identified by peptide sequencing using the tandem mass spectrometry (MS/MS) mode of operation in which a mass spectrometer uses two or more mass analyzers.
precursor ions
After an initial mass analysis, individual peptide ions in the mass spectrum can be selected. The selected ions are known as ________.
product ions
A precursor ion is then subjected to the second round of fragmentation through collision and is broken into smaller ions known as _______.
top-down strategy
In ________, intact proteins in a complex mixture are fractionated and separated into less complex protein mixtures or single proteins.
bottom-up strategy
The ________ is commonly used for high-throughput analysis of small peptides derived from highly complex samples.
Sort-then-break approach
Proteins in a complex mixture are first isolated and then enzymatically cleaved.
Break-then-sort approach
Also known as the shotgun approach, wherein proteins are cleaved first and the resulting peptide mixture is then separated by LC and analyzed by tandem MS.
Human Microbiota
Microbial community.
Metagenomics
Allows the study of the microbial genome of complete microbial communities harvested directly from natural environments.
5S and 23S rRNA genes
encode the RNA components of the large subunit of the ribosome.
16S rRNA gene
encodes the RNA component of the small subunit of the ribosome.
intergenic spacer region (ISR)
The _______ between the 16S rRNA and 23S rRNA genes in the rRNA operon is another commonly used marker.
Fluorescence
The emission of light by a fluorophore.
Fluorophore
A moiety in a molecule that fluoresces on absorbing the energy from an excitation light source or radiation.
Raman spectroscopy
Utilizes a near-infrared excitation light source and measures the scattering of laser light caused by the vibrating molecules of a sample.
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