[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fEEuQEikn_M4-Zv5lFajk-iqTPv1gEMtGtHdN8yuAWLg":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":47},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":36,"seoTitle":37,"seoDescription":37,"author":38,"createdDate":39,"lastUpdatedDate":40,"draft":41,"category":42,"image":37,"body":43,"faq":44,"tags":45,"related":46},"galactomannan-test-for-invasive-aspergillosis","Galactomannan Test for Invasive Aspergillosis",null,"Acharya Tankeshwar","2022-05-15","2025-12-29",false,"mycology","Galactomannan (GM) is a polysaccharide constituent of the cell walls of *Aspergillus*. It is a carbohydrate molecule with a mannose backbone. Galactomannan is released from the cell wall of *Aspergillus* hyphae during growth in vivo. In person with invasive aspergillosis, there may be high titers of galactomannan antigen in serum and bronchoalveolar lavage (BAL) fluid. Although the sensitivity and specificity of the galactomannan detection test vary based on settings and nature of test kits used, this test is a major milestone for the early detection of aspergillosis in patients at risk of developing the disseminated disease.\n\nGM index is also used as a prognostic marker. Monitoring galactomannan level in the blood of a patient at risk allows the clinician to follow trends and take appropriate actions.\n\n## Test Methods\n\nGalactomannan is the main antigen used as a diagnostic marker in commercially available kits for the diagnosis of invasive aspergillosis (IA). Both lateral flow assay (LFA) and enzyme immunoassay (EIA) are available for the detection of this antigen in the serum or BAL sample of the patient.\n\n### Platelia Aspergillus Galactomannan Enzyme Immunoassay\n\nPlatelia *Aspergillus* GM EIA (Bio-Rad, Marne La Coquette, France) is a double sandwich enzyme immunoassay that utilizes a rat monoclonal antibody EBA-2 directed against the galactofuranoside side chain of the GM antigen.\n\nThe monoclonal antibodies are used\n\n1. To coat the wells of the microplate and bind the antigen, and\n2. To detect the antigen bound to the sensitized microplate (conjugate reagent: peroxidase-linked monoclonal antibodies)\n\n![Platelia Aspergillus Galactomannan Enzyme Immunoassay - PlateliaAspergillusGalactomannan Enzyme Immunoassay](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FPlatelia-Aspergillus-Galactomannan-Enzyme-Immunoassay.jpg)Figure: Platelia Aspergillus Galactomannan Enzyme Immunoassay\n\nIn the presence of galactomannan antigen, a monoclonal antibody-galactomannan-monoclonal antibody\u002Fperoxidase complex is formed. Chromogen TMB solution is added. This in turn will react with the complexes bound to the well to form a blue color reaction. The enzyme reaction is stopped by the addition of acid, which changes the blue color to yellow. The absorbance of specimens and controls is determined with a [spectrophotometer](\u002Fspectrophotometer-principle-parts-types-uses\u002F) set at 450 and 620\u002F630 nm wavelength.\n\nFind more information from the manufacturer [here](https:\u002F\u002Fwww.bio-rad.com\u002Fen-np\u002Fproduct\u002Fplatelia-aspergillus-ag).\n\n### IMMY sōna Aspergillus GM Lateral Flow Assay\n\nThe sōna *Aspergillus* galactomannan lateral flow assay is an immunochromatographic test system for the qualitative detection of *Aspergillus* galactomannan in serum and BAL samples. It is a sandwich immunochromatographic test system.\n\nSerum and BAL specimens require heat pre-treatment prior to testing. After pre-treatment, the sample is pipetted into a clean tube, and a drop of Running Buffer (REF AFLFRB) is added, followed by an LFA strip (REF LFAF50). The test is run for 30 minutes and the results can be read within 10 minutes of completing the test.\n\n![sona galactomannan Lateral Flow Assay - sona galactomannan Lateral Flow Assay](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fsona-galactomannan-Lateral-Flow-Assay.png)Figure: sona galactomannan Lateral Flow Assay\n\n*Aspergillus* Galactomannan specific antibodies is present in the LFA conjugated to colloidal gold. This antibodies then binds to any galactomannan that may be present in the specimen that moves upward. If any binding occurs, the antibody-antigen complex will migrate up the strip by capillary flow until it is captured by the *Aspergillus* Galactomannan specific antibodies in the test line. This results in the formation of a visible test line.\n\nAdditionally, control antibodies conjugated to gold are present that move along with the specimen. The particle will be captured by the control antibodies present on the control line, regardless of positive or negative test results. Positive test results create two lines (test and control lines) and negative results form only one line (control line). If a control line fails to develop, the test is not valid.\n\nFind more information from the manufacturer [here](https:\u002F\u002Fwww.immy.com\u002Fasp).\n\n### Aspergillus Lateral-Flow Device\n\nThe Aspergillus LFD (AspLFD) is a rapid immunochromatography test developed by OLM Diagnostic. This is useful for the qualitative detection of Aspergillus diagnostic antigen in the human serum and BAL in patients with suspected invasive pulmonary Aspergillosis.\n\n![Lateral flow devices, showing from left to right a negative result, followed by increasing test line intensity. - Lateral flow devices, showing from left to right a negative result, followed by increasing test line intensity. (source)](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FOLM-Aspergillosis-diagnosis.jpeg)Figure: Lateral flow devices, showing from left to right a negative result, followed by increasing test line intensity. (source)\n\nAspLFD uses a monoclonal Ab conjugated to nitrocellulose beads (NCB) to detect *Aspergillus* diagnostic antigen. The antibody-NCB conjugate binds specifically to *Aspergillus* diagnostic antigen in the patient sample to form a complex. The complex migrates along the strip until it is captured. These are then concentrated on the test zone (T), where the same antibody has been bound.\n\nThis causes a red line to appear on the strip. If antigen concentrations are below detectable levels, no visible test line will be produced. Uncaptured NCB conjugate continues to flow towards the end of the strip where it is bound on the control (C) zone. The formation of a red C line indicates the test has been performed correctly.\n\nFind more information from the manufacturer [here](http:\u002F\u002Folmdiagnostics.com\u002Fproducts\u002F#aspdx).\n\n## Limitations\n\n1. Although GM is a useful marker for IA, there are many causes of false positivity. Piperacillin\u002Ftazobactam or amoxicillin with clavulanic acid, PlasmaLyte, and certain foodstuffs, including pasta, vegetables, and milk are all known to cause false positives.\n2. Several other fungal genera such as *Penicillum, Alternaria, Rhodotorula, Paecilomyces*, *Cryptococcus, Blastomyces,* and *Histoplasma* are known to be reactive and give false-positive results. For example, cryptococcal galactoxylomannan contains an epitope that cross-reacts with the galactomannan antigen of *Aspergillus*spp., which is the antigen target of the Platelia *Aspergillus* assay. Please refer to manufacturer guidelines for the cross-reactivity of their process.\n3. Detection of GM may be reduced in patients with chronic granulomatous disease and patients treated with mold-active antifungals.",[],[],[],[48,54,61,66,70,74,79,84,88,92],{"slug":49,"name":38,"description":50,"image":51,"body":52,"postCount":53},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":55,"name":56,"description":57,"image":58,"body":59,"postCount":60},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":62,"name":63,"description":64,"image":37,"body":37,"postCount":65},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":67,"name":68,"description":64,"image":37,"body":37,"postCount":69},"samikshya-acharya","Samikshya Acharya",20,{"slug":71,"name":72,"description":64,"image":37,"body":37,"postCount":73},"alisha-tripathi","Alisha Tripathi",6,{"slug":75,"name":76,"description":77,"image":37,"body":37,"postCount":78},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":80,"name":81,"description":82,"image":37,"body":37,"postCount":83},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":85,"name":86,"description":64,"image":37,"body":37,"postCount":87},"srijana-khanal","Srijana Khanal",18,{"slug":89,"name":90,"description":82,"image":37,"body":37,"postCount":91},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":93,"name":94,"description":64,"image":37,"body":95,"postCount":96},"nisha-rijal","Nisha Rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]