Diagnostic Tests in Microbiology

<p>To distinguish between different organisms based on metabolic characteristics</p> Signup and view all the answers

<p>Evidence of infection</p> Signup and view all the answers

<p>Selectively supports growth of Gram-positive bacteria and differentiates mannitol fermentation</p> Signup and view all the answers

<p>The likelihood of false positives occurring</p> Signup and view all the answers

<p>To ensure an uncontaminated sample</p> Signup and view all the answers

<p>Clumping occurs</p> Signup and view all the answers

<p>It is non-fluorescent and targets the antigen</p> Signup and view all the answers

<p>Fluorescein isothiocyanate (FITC)</p> Signup and view all the answers

<p>488 nm</p> Signup and view all the answers

<p>Diagnosing viral pathogens</p> Signup and view all the answers

<p>Fluorescent antibodies</p> Signup and view all the answers

<p>To convert a colourless compound into a coloured compound</p> Signup and view all the answers

<p>Indirect EIA</p> Signup and view all the answers

<p>It facilitates clumping for identification</p> Signup and view all the answers

<p>Sandwich EIA</p> Signup and view all the answers

<p>Identifying microorganisms in patient samples</p> Signup and view all the answers

<p>Indirect involves a secondary fluorescent antibody, while direct does not</p> Signup and view all the answers

<p>They must bind to different sites of target antigen</p> Signup and view all the answers

<p>To detect disease before culturing test results are available</p> Signup and view all the answers

<p>To detect the presence of antibodies</p> Signup and view all the answers

<p>The enzyme converts substrates to generate a color reaction</p> Signup and view all the answers

<p>MacConkey agar</p> Signup and view all the answers

<p>Blood agar</p> Signup and view all the answers

<p>Enterotube II</p> Signup and view all the answers

<p>Gram negative and positive bacteria</p> Signup and view all the answers

<p>Agglutination</p> Signup and view all the answers

<p>Insoluble complexes or precipitates form</p> Signup and view all the answers

<p>In agarose gel</p> Signup and view all the answers

<p>To detect bacterial surface antigens</p> Signup and view all the answers

<p>A combined biochemical profile</p> Signup and view all the answers

<p>Serological testing</p> Signup and view all the answers

<p>To identify specific enteric bacteria</p> Signup and view all the answers

<p>Acid-fast stain</p> Signup and view all the answers

<p>E.coli</p> Signup and view all the answers

<p>Dermatophytes</p> Signup and view all the answers

<p>To rapidly identify infectious diseases</p> Signup and view all the answers

<p>Cycles of heating and cooling</p> Signup and view all the answers

<p>It can quantify the amount of target DNA</p> Signup and view all the answers

<p>Non-specific fluorescent probe</p> Signup and view all the answers

<p>To convert RNA to cDNA for amplification</p> Signup and view all the answers

<p>Amplification of cDNA</p> Signup and view all the answers

<p>To detect the fluorescence of specific targets in real time</p> Signup and view all the answers

<p>RNA viruses</p> Signup and view all the answers

<p>Clumping of latex beads</p> Signup and view all the answers

<p>Immunofluorescence</p> Signup and view all the answers

<p>Involves non-fluorescent primary antibody</p> Signup and view all the answers

<p>Fluorescein isothiocyanate (FITC)</p> Signup and view all the answers

<p>To amplify the fluorescent signal</p> Signup and view all the answers

<p>Identifying microorganisms</p> Signup and view all the answers

<p>Directly tags the antibody with a fluorescent dye</p> Signup and view all the answers

<p>Requirement for a secondary fluorescent antibody</p> Signup and view all the answers

<p>They enhance the color reaction for better visibility.</p> Signup and view all the answers

<p>It detects antigens using two antibodies.</p> Signup and view all the answers

<p>They fluoresce when excited by a specific wavelength of light.</p> Signup and view all the answers

<p>Indirect EIA</p> Signup and view all the answers

<p>Fluorescent microscopy using fluorophores</p> Signup and view all the answers

<p>It can be excited by a 488 nm laser line.</p> Signup and view all the answers

<p>It detects antigens with low sensitivity.</p> Signup and view all the answers

<p>It must be colorless to begin with.</p> Signup and view all the answers

<p>It detects antibodies bound to specific antigens using fluorescent dyes.</p> Signup and view all the answers

<p>By visualizing the clumping of latex beads with bound antibodies.</p> Signup and view all the answers

<p>Indirect immunofluorescence.</p> Signup and view all the answers

<p>They provide results in real-time without laboratory equipment.</p> Signup and view all the answers

<p>Binding of primary antibodies to antigens.</p> Signup and view all the answers

<p>To form stable complexes with antigens for detection.</p> Signup and view all the answers

<p>They amplify the antibody-antigen interactions visually.</p> Signup and view all the answers

<p>To create a visible signal upon binding to target molecules.</p> Signup and view all the answers

<p>Detecting antibodies against specific pathogens.</p> Signup and view all the answers

<p>Agglutination tests.</p> Signup and view all the answers

<p>Lateral flow immunoassay.</p> Signup and view all the answers

<p>The specificity of the fluorochrome used.</p> Signup and view all the answers

<p>Fluorescent staining techniques.</p> Signup and view all the answers

<p>Specificity for particular antigens to ensure accurate results.</p> Signup and view all the answers

<p>Indirect staining utilizes tagged secondary antibodies, while direct staining does not.</p> Signup and view all the answers

<p>Primary antibody</p> Signup and view all the answers

<p>Fluorescein isothiocyanate (FITC)</p> Signup and view all the answers

<p>Identification of viral pathogens in patient samples.</p> Signup and view all the answers

<p>It amplifies the fluorescence signal.</p> Signup and view all the answers

<p>To allow for visualization under ultraviolet light.</p> Signup and view all the answers

<p>They facilitate the identification of specific antigens.</p> Signup and view all the answers

<p>Indirect staining using a secondary fluorescent antibody.</p> Signup and view all the answers

<p>It can quantify antigens rapidly and accurately.</p> Signup and view all the answers

<p>It allows the antibody to bind to a specific antigen.</p> Signup and view all the answers

<p>Chromogens are responsible for color change upon reaction.</p> Signup and view all the answers

<p>It can be directly applied to living tissues without fixation.</p> Signup and view all the answers

<p>Antibodies must bind to different epitopes on the target antigen.</p> Signup and view all the answers

<p>Indirect EIA</p> Signup and view all the answers

<p>Their affinity for binding to distinct antigens.</p> Signup and view all the answers

<p>They are less sensitive than indirect assays.</p> Signup and view all the answers

<p>Utilizing a secondary antibody</p> Signup and view all the answers

<p>To visualize the presence of a specific antigen</p> Signup and view all the answers

<p>The affinity of the primary antibody to the antigen</p> Signup and view all the answers

<p>They emit light when excited, allowing visualization</p> Signup and view all the answers

<p>It may have lower sensitivity than indirect methods</p> Signup and view all the answers

<p>It must be conjugated to a stable fluorophore</p> Signup and view all the answers

<p>It improves signal amplification</p> Signup and view all the answers

<p>Their specificity for antigens</p> Signup and view all the answers

<p>A primary antibody binds to the antigen, followed by a labeled secondary antibody</p> Signup and view all the answers

<p>Antibody specificity for distinct antigens</p> Signup and view all the answers

<p>To stabilize fluorophores during imaging</p> Signup and view all the answers

<p>They can recognize multiple epitopes on the same antigen</p> Signup and view all the answers

<p>The substrate for the enzyme</p> Signup and view all the answers

<p>Aseptic technique, sample size, and environmental conditions of the potential pathogen are critical.</p> Signup and view all the answers

<p>Selective media inhibits the growth of certain organisms while promoting others, whereas enrichment culture supports the growth of numerous organisms.</p> Signup and view all the answers

<p>Differential media distinguishes organisms based on their metabolic activities, often using pH indicators.</p> Signup and view all the answers

<p>A urine sample allows for direct microscopy to assess bacteria presence and viable counts indicating infection.</p> Signup and view all the answers

<p>High specificity reduces the likelihood of false positives, ensuring accurate pathogen identification.</p> Signup and view all the answers

<p>It indicates a urinary tract infection, prompting further diagnostic and therapeutic actions.</p> Signup and view all the answers

<p>A dichotomous key aids in the identification of organisms through a series of choices based on characteristics.</p> Signup and view all the answers

<p>Maintaining sterile conditions prevents contamination of samples, ensuring accurate diagnostic results.</p> Signup and view all the answers

<p>It indicates a positive result for the presence of S.aureus.</p> Signup and view all the answers

<p>They are used to detect specific antigens in cells.</p> Signup and view all the answers

<p>Indirect staining involves a primary non-fluorescent antibody and a secondary fluorescent antibody, while direct staining uses a single fluorescently tagged antibody.</p> Signup and view all the answers

<p>It targets the primary antibody and is conjugated to a fluorescent dye.</p> Signup and view all the answers

<p>FITC serves as a fluorescent dye that tags antibodies for the detection of antigens.</p> Signup and view all the answers

<p>Viral pathogens are commonly identified using this method.</p> Signup and view all the answers

<p>Immunofluorescence can be used for disease diagnosis by identifying specific microorganisms in patient samples.</p> Signup and view all the answers

<p>It implies the absence of S.aureus in the tested sample.</p> Signup and view all the answers

<p>GFP allows for visualization of biological processes in real-time without harming the living cells.</p> Signup and view all the answers

<p>A chromogen reacts with an enzyme to produce a color change, indicating the presence of an antigen or antibody.</p> Signup and view all the answers

<p>Direct EIA detects antigens directly, while sandwich EIA quantitatively measures antigens using two antibodies.</p> Signup and view all the answers

<p>Binding to different sites increases sensitivity and ensures reliable antigen detection.</p> Signup and view all the answers

<p>It enables the visualization of cellular and molecular processes, potentially identifying diseases before culture results are available.</p> Signup and view all the answers

<p>Applying fluorophores to host tissue enables in vivo imaging of biological processes and disease states.</p> Signup and view all the answers

<p>Indirect EIA allows for the detection of antibodies and provides higher sensitivity due to signal amplification.</p> Signup and view all the answers

<p>The effectiveness is determined by its ability to react with specific substrates to produce a measurable color change.</p> Signup and view all the answers

<p>Antibodies bind to specific antigens in the sample, forming a complex that can be detected by retaining the beads on the test line.</p> Signup and view all the answers

<p>qPCR allows for real-time quantification of DNA through fluorescence, eliminating the need for subsequent gel electrophoresis.</p> Signup and view all the answers

<p>Reverse transcription converts RNA into complementary DNA (cDNA), which can then be amplified during PCR.</p> Signup and view all the answers

<p>PCR uses cycles of denaturation, annealing with primers, and extension to create multiple copies of target DNA sequences.</p> Signup and view all the answers

<p>Both specific fluorescent probes, which target unique sequences, and non-specific probes, which fluoresce upon binding to any double-stranded DNA, can be utilized.</p> Signup and view all the answers

<p>The test line contains fixed antibodies that capture antibody-bound antigen or beads, indicating a positive result.</p> Signup and view all the answers

<p>RT-qPCR directly detects viral RNA, enabling quick and accurate identification of RNA viruses in a sample.</p> Signup and view all the answers

<p>The fluorometer detects fluorescence emitted during the amplification process, allowing for real-time monitoring of DNA quantity.</p> Signup and view all the answers

<p>It selectively inhibits the growth of non-enteric bacteria.</p> Signup and view all the answers

<p>It provides a biochemical profile based on the fermentation of sugars and hydrogen sulfide production.</p> Signup and view all the answers

<p>To simultaneously inoculate multiple media for rapid identification of gram negative rods.</p> Signup and view all the answers

<p>The presence of antibodies binding to specific antigens.</p> Signup and view all the answers

<p>They indicate the presence of an immune response against a specific pathogen.</p> Signup and view all the answers

<p>It forms an insoluble complex when soluble antibodies and antigens meet.</p> Signup and view all the answers

<p>It uses fluorescently tagged antibodies to visualize the presence of antigens in samples.</p> Signup and view all the answers

<p>It indicates urease production by the microorganism.</p> Signup and view all the answers

<p>It determines the ability of bacteria to convert tryptophan to indole.</p> Signup and view all the answers

<p>Acid-fast staining is used specifically for identifying mycobacteria and certain parasites.</p> Signup and view all the answers

<p>By observing visible clumping of particles when antibodies bind to specific antigens.</p> Signup and view all the answers

<p>It assists in the stepwise identification of organisms based on their biochemical characteristics.</p> Signup and view all the answers

<p>It indicates the organism is capable of producing hydrogen sulfide from sulfur-containing compounds.</p> Signup and view all the answers

<p>It combines electrophoresis and antibody-binding to identify specific proteins related to pathogens.</p> Signup and view all the answers

<p>The potential pathogen's preferred growth conditions and survival requirements must be considered.</p> Signup and view all the answers

<p>Enrichment culture media supports the growth of a variety of microorganisms from a sample, allowing for the isolation of specific pathogens.</p> Signup and view all the answers

<p>A test with high sensitivity can detect very small amounts of a pathogen, reducing the chance of false negatives.</p> Signup and view all the answers

<p>Selective media contains specific chemicals that inhibit the growth of unwanted organisms while promoting the growth of target microorganisms.</p> Signup and view all the answers

<p>Differential media distinguishes between different organisms based on their metabolic activities and pH changes, aiding identification.</p> Signup and view all the answers

<p>Direct microscopy gives an estimate of the number of bacteria present in the urine sample.</p> Signup and view all the answers

<p>A viable count refers to the number of living bacteria that can grow and form colonies on culture media.</p> Signup and view all the answers

<p>Using a sterile swab prevents contamination of the specimen, ensuring accurate diagnostic results.</p> Signup and view all the answers

<p>Clumping of the latex beads indicates a positive result.</p> Signup and view all the answers

<p>Direct immunofluorescence uses a fluorescently tagged primary antibody, while indirect immunofluorescence uses a non-fluorescent primary antibody and a fluorescent secondary antibody.</p> Signup and view all the answers

<p>FITC is a fluorescent dye used to tag antibodies in the direct staining method.</p> Signup and view all the answers

<p>Immunofluorescence allows for specific detection of antigens associated with pathogens using fluorescently labeled antibodies.</p> Signup and view all the answers

<p>The secondary antibody amplifies the signal by binding to the primary antibody, which is non-fluorescent.</p> Signup and view all the answers

<p>It refers to the use of immunofluorescence to identify infectious agents and diagnose diseases.</p> Signup and view all the answers

<p>The latex beads are coated with antibodies that specifically bind to S.aureus, causing visible clumping when the bacteria are present.</p> Signup and view all the answers

<p>Samples from body fluids, tissues, or cells can be analyzed using immunofluorescence.</p> Signup and view all the answers

<p>Capillary action pulls the sample through a matrix, allowing it to interact with antibody-coated beads.</p> Signup and view all the answers

<p>PCR amplifies specific DNA segments to create many copies for analysis.</p> Signup and view all the answers

<p>qPCR quantifies the amount of DNA in real-time using fluorescent probes.</p> Signup and view all the answers

<p>The fluorometer detects fluorescence to determine the amount of amplified DNA.</p> Signup and view all the answers

<p>Reverse transcription converts RNA into complementary DNA (cDNA) for amplification.</p> Signup and view all the answers

<p>The complexes retain beads on a test line, indicating a positive result.</p> Signup and view all the answers

<p>Specific fluorescent probes fluoresce only when they bind to their target DNA.</p> Signup and view all the answers

<p>RT-qPCR is particularly useful for detecting RNA viruses.</p> Signup and view all the answers

<p>They use an enzyme-bound antibody that reacts with substrates to produce a color reaction, indicating the presence of antigens.</p> Signup and view all the answers

<p>The chromogen is a colorless compound that is converted into a colored compound by chemical reactions, enabling visual detection of reactions.</p> Signup and view all the answers

<p>GFP can be excited by specific wavelengths of light, allowing visualization of tagged structures in cells.</p> Signup and view all the answers

<p>The Sandwich EIA method is designed to quantify antigens quickly and accurately.</p> Signup and view all the answers

<p>The variable end of the antibody is free to bind to the antigen, allowing for specific antigen detection.</p> Signup and view all the answers

<p>It may help detect diseases by allowing the visualization of fluorophore-labeled components before culturing test results are available.</p> Signup and view all the answers

<p>Direct EIA detects antigens directly, while Indirect EIA detects antibodies in response to the antigens.</p> Signup and view all the answers

<p>Binding to different sites on the antigen ensures the formation of a stable immune complex required for accurate detection.</p> Signup and view all the answers

<p>It differentiates lactose fermenters from non-lactose fermenters.</p> Signup and view all the answers

<p>It indicates the ability of an organism to convert tryptophan into indole.</p> Signup and view all the answers

<p>It indicates the fermentation of sugars and potential gas and hydrogen sulfide production.</p> Signup and view all the answers

<p>It allows for simultaneous inoculation of multiple media for rapid identification of gram negative rods.</p> Signup and view all the answers

<p>Gram staining is used for this classification.</p> Signup and view all the answers

<p>It detects antibodies in the patient serum that indicate infection with specific pathogens.</p> Signup and view all the answers

<p>Precipitation occurs when soluble antibodies and antigens combine to form an insoluble complex.</p> Signup and view all the answers

<p>Agglutination visualizes the clumping of particles that occurs when antibodies bind to antigens.</p> Signup and view all the answers

<p>It targets bacterial surface antigens like Protein A and clumping factor in Staphylococcus.</p> Signup and view all the answers

<p>It gives a biochemical profile that aids in the identification of the organism.</p> Signup and view all the answers

<p>It identifies organisms, such as Mycobacterium, that retain dye despite acid washing.</p> Signup and view all the answers

<p>It utilizes enzyme-linked antibodies to detect antigens or antibodies in a sample.</p> Signup and view all the answers

<p>It allows for the observation of live motile organisms, fungi, and parasites in their natural state.</p> Signup and view all the answers

<p>It identifies fungi and Acanthamoeba by highlighting their polysaccharides.</p> Signup and view all the answers