Nucleic acid extractors play a crucial role in clinical diagnosis. The following is a detailed introduction to their applications:

I. Diagnosis of Infectious Diseases

1. Detection of Viral Infections
   • COVID – 19 Virus Detection
     During the global COVID – 19 pandemic prevention and control efforts, nucleic acid extractors are key devices. They can efficiently extract the nucleic acid of the novel coronavirus (SARS – CoV – 2) from samples such as patients’ nasopharyngeal swabs, oropharyngeal swabs, sputum, or blood. The extracted nucleic acid is then used for real – time reverse transcription quantitative polymerase chain reaction (RT – qPCR) detection. Since nucleic acid testing for the COVID – 19 virus is an important basis for diagnosing infection, the rapid and accurate extraction ability of nucleic acid extractors helps to identify infected individuals in a timely manner, buying precious time for pandemic prevention and control. For example, in large – scale nucleic acid testing, automated nucleic acid extractors can process a large number of samples in a short time, improving the detection efficiency.
   • Influenza Virus Detection
     For seasonal influenza viruses (such as influenza A virus subtypes H1N1, H3N2, and influenza B virus), nucleic acid extractors can extract the viral nucleic acid from samples such as patients’ nasal secretions, pharyngeal swabs, or sputum. Through nucleic acid detection techniques, different subtypes of influenza viruses can be distinguished, and the virus can be detected in the early stage of infection. This is crucial for taking timely isolation and treatment measures to prevent the spread of the influenza virus.
   • Human Immunodeficiency Virus (HIV) Detection
     In HIV testing, nucleic acid extractors extract the viral RNA from the blood samples of suspected infected individuals. Compared with traditional antibody testing, nucleic acid testing can detect HIV infection earlier, especially during the “window period” after infection when antibodies have not yet been produced, but viral nucleic acid is already present. This is very important for early diagnosis and timely initiation of antiviral treatment, helping to control the progression of the disease and reduce the risk of transmission.
   • Detection of Other Viruses
     This includes the detection of infections such as human papillomavirus (HPV), cytomegalovirus (CMV), and Ebola virus. Taking HPV testing as an example, nucleic acid extractors can extract the viral nucleic acid from cervical smears or tissue samples, which is used to determine whether there is an HPV infection and identify the viral type. It is of great significance for the early screening and prevention of cervical cancer, as the persistent infection of certain high – risk HPV types is the main cause of cervical cancer.
2. Detection of Bacterial Infections
   • Tuberculosis Detection
     Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Nucleic acid extractors can extract the bacterial DNA from samples such as patients’ sputum, pleural effusion, cerebrospinal fluid, or tissue samples (such as lymph node biopsy tissue). Through nucleic acid amplification detection techniques (such as polymerase chain reaction, PCR), Mycobacterium tuberculosis can be rapidly detected, and drug – resistant and drug – sensitive strains of Mycobacterium tuberculosis can be distinguished. This is crucial for the accurate diagnosis and effective treatment of tuberculosis, as the treatment regimens for drug – resistant and drug – sensitive tuberculosis are different.
   • Sepsis Detection
     Sepsis is a severe systemic infectious disease usually caused by bacteria entering the bloodstream and multiplying in large numbers. Nucleic acid extractors can extract the bacterial DNA from patients’ blood samples. By detecting the bacterial nucleic acid in the blood, it can be quickly determined whether there is sepsis and the type of bacteria causing it. This early detection helps to promptly use targeted antibiotics for treatment, improving the survival rate of patients.
   • Detection of Other Bacterial Infections
     For example, the detection of bacterial infections such as Escherichia coli causing urinary tract infections and Streptococcus pneumoniae causing pneumonia. Extracting the bacterial nucleic acid from samples such as urine and sputum can accurately diagnose the source of infection, providing a basis for the rational selection of antibiotics.
3. Detection of Parasitic Infections
   • Malaria Detection
     Malaria is a parasitic disease caused by Plasmodium. Nucleic acid extractors can extract the nucleic acid of Plasmodium from patients’ blood samples. Through nucleic acid detection techniques, the pathogen can be detected at an early stage of infection when the number of Plasmodium is relatively small. This is more sensitive than the traditional method of microscopic examination of Plasmodium. Early diagnosis of malaria is very important for timely administration of antimalarial drugs, preventing the progression of the disease and its spread.
   • Schistosomiasis Detection
     Schistosomiasis is a disease caused by the parasitism of Schistosoma in the human body. Nucleic acid of Schistosoma is extracted from patients’ feces or blood samples for the detection of Schistosoma infection. For patients with chronic schistosomiasis, nucleic acid testing can detect potential infections, as there may be no obvious clinical symptoms in the chronic stage, but nucleic acid testing can detect the presence of Schistosoma, which helps with timely treatment and control of disease transmission.

II. Diagnosis of Genetic Diseases

1. Diagnosis of Chromosomal Diseases
   • Diagnosis of Down Syndrome (Trisomy 21)
     In prenatal diagnosis, nucleic acid extractors extract the fetal DNA from samples obtained by amniocentesis or chorionic villus sampling. Through chromosomal karyotype analysis or fluorescence in situ hybridization (FISH) technology based on nucleic acids, it can be accurately detected whether the fetus has trisomy 21. This early diagnosis provides families with the opportunity to make choices, such as deciding whether to continue the pregnancy, and also prepares for post – natal medical interventions.
   • Diagnosis of Other Chromosomal Diseases
     This includes the diagnosis of chromosomal numerical abnormalities such as trisomy 18, trisomy 13, and chromosomal structural abnormalities (such as chromosomal translocations, deletions, duplications). Nucleic acid extractors provide high – quality DNA samples for the genetic testing of these diseases, helping doctors to determine the chromosomal abnormalities of the fetus or patient.
2. Diagnosis of Monogenic Genetic Diseases
   • Thalassemia Diagnosis
     Thalassemia is a common monogenic genetic disease. Nucleic acid extractors extract DNA from the peripheral blood of patients or from the chorionic villi and amniotic fluid of the fetus. Through gene sequencing or specific gene detection methods, mutations in genes related to thalassemia (such as the α – globin gene and β – globin gene) can be detected. Accurate genetic diagnosis helps to determine the severity of the patient’s condition, provides a basis for treatment plans (such as blood transfusion, hematopoietic stem cell transplantation), and can predict whether the fetus is affected in prenatal diagnosis.
   • Cystic Fibrosis Diagnosis
     Cystic fibrosis is a genetic disease that affects the exocrine glands. After extracting the patient’s DNA using a nucleic acid extractor, gene detection techniques can be used to search for mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Early diagnosis of cystic fibrosis is very important for disease management and treatment (such as drug treatment, physical therapy), and can also provide genetic counseling services for families.

III. Tumor Diagnosis and Monitoring

1. Early Tumor Diagnosis
   • Circulating Tumor DNA (ctDNA) Detection
     In the blood of tumor patients, there is a small amount of ctDNA, which carries the gene mutation information of tumor cells. Nucleic acid extractors can extract ctDNA from blood samples, and then through highly sensitive gene detection techniques (such as digital PCR, next – generation sequencing), detect mutations in tumor – related genes (such as oncogenes, tumor suppressor genes). For example, in the early stages of various cancers such as lung cancer, colorectal cancer, and breast cancer, ctDNA detection can be used as a non – invasive detection method to assist imaging examinations and other traditional detection methods in detecting tumor signs earlier.
   • MicroRNA (miRNA) Detection
     miRNAs are a class of small – molecule RNAs that play an important regulatory role in the occurrence and development of tumors. Nucleic acid extractors extract miRNAs from samples such as patients’ blood, tissues, or body fluids. By detecting changes in the expression levels of miRNAs, they can be used as biomarkers for early tumor diagnosis. For example, the expression levels of certain miRNAs change specifically in the early stage of liver cancer, and detecting these changes can provide clues for the early detection of liver cancer.
2. Tumor Treatment Monitoring
   • Evaluation of Treatment Efficacy
     After tumor patients receive surgery, chemotherapy, radiotherapy, or targeted therapy, nucleic acid extractors can regularly extract nucleic acids from the patients’ blood, tissues, or other body fluid samples. By detecting changes in the content of tumor – related nucleic acid markers (such as ctDNA, miRNA), the effectiveness of treatment can be evaluated. If the content of these markers decreases after treatment, it indicates that tumor cells have been effectively killed and the treatment plan is effective. Conversely, if the marker content increases or new gene mutations occur, it may suggest tumor recurrence or the development of drug resistance, and the treatment plan needs to be adjusted.
   • Monitoring of Drug Resistance
     As tumor treatment progresses, tumor cells may develop drug resistance. By extracting the nucleic acid of tumor cells using a nucleic acid extractor and detecting changes in the expression or gene mutations of drug – resistance – related genes (such as the multi – drug resistance gene 1, MDR1), signs of drug resistance in tumor cells can be detected in a timely manner. This helps doctors adjust treatment strategies in advance, such as changing drugs or combining other treatment methods, to improve the treatment effect.