Molecular Genetic HLA -Typing High Resolution ( Recipiant ) - NGS
Test Code
MOG92
Also Known As
No data available
Test Parameters Included
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Department
MOLECULAR GENETICS
Methodology
NGS (Next-Generation Sequencing)
Next-Generation Sequencing (NGS) has emerged as the most comprehensive and reliable method for high-resolution HLA typing. This technology is crucial for providing the detailed and unambiguous genetic information required to find a compatible donor for a transplant recipient. The methodology is identical to the process used for a donor, but the clinical context is focused on the patient in need of the transplant. The detailed steps are as follows:
* DNA Extraction: High-quality genomic DNA is isolated from the recipient's whole blood sample. The integrity and concentration of the DNA are carefully assessed, as they are essential for successful downstream sequencing.
* PCR Amplification: The key regions of the HLA genes (e.g., HLA-A, -B, -C, -DRB1, -DQB1) are targeted and amplified using Polymerase Chain Reaction (PCR). The primers are designed to amplify all known alleles within these specific gene regions.
* Library Preparation: The amplified DNA fragments are then processed to create a sequencing library. This involves fragmenting the DNA and ligating adapter sequences that are essential for the sequencing process. A unique barcode is also added to the sample, allowing for multiple samples to be sequenced simultaneously in a single run.
* Massive Parallel Sequencing: The prepared DNA library is loaded onto a high-throughput sequencing platform. The instrument sequences millions of DNA fragments in parallel, generating vast amounts of raw data. This massive parallel approach is the core of NGS, enabling comprehensive coverage of all HLA loci.
* Bioinformatic Analysis: The raw sequencing data is then analyzed using advanced bioinformatics software. The software aligns the sequenced fragments to a vast and continuously updated HLA reference database (e.g., the IPD-IMGT/HLA Database). This alignment allows for the precise determination of the nucleotide sequence and the definitive identification of the specific allele at each HLA locus. NGS's sequencing depth effectively resolves any genetic ambiguities, providing a complete, high-resolution genotype.
* Report Generation: The final genotype, expressed at the allele level (e.g., A*02:01:01:01), is generated, providing the essential genetic blueprint for the donor matching process.
Sample Required
RECIPIENT WB EDTA
* Preferred Sample: Whole Blood (WB) from the recipient is collected in a Lavender-top tube containing the anticoagulant EDTA (ethylenediaminetetraacetic acid). This is the standard sample for molecular genetic testing due to its stability and high yield of genomic DNA.
* Volume: A minimum of 3-5 mL of whole blood is typically required.
* Handling and Transport: The tube should be gently inverted to mix the blood with the EDTA to prevent clotting. The sample must be transported to the laboratory under refrigerated conditions (2-8°C). Whole blood is stable for several days at this temperature, but prompt delivery is always recommended. Freezing of the whole blood sample is generally discouraged as it can damage the cells and compromise DNA quality.
* Alternate Samples: In rare cases where a blood sample is not available, other sources of DNA such as bone marrow aspirate can be used, but whole blood remains the preferred choice.
Preparation
* No special preparation is required. Fasting is not necessary, as DNA is a stable molecule and is not affected by food or drink. * No dietary or lifestyle restrictions are needed. * Timing: The blood... Read more
Schedule Report
15 Days
Emergency Report
Yes
Frequently Asked Questions
No data available
Test Description
- High-end laboratory & medical equipment.
- Outstanding doctor team.
- Personalized care & high-quality service.
- Tailormade health screening packages.