Telomerase

Telomerase is a special reverse transcriptase consisting of RNA and protein involved in the synthesis of telomeres (a specific nucleotide sequence and structure) at the DNA ends of eukaryotic cells. The telomere length of normal somatic cells is gradually shortened as the cell divides, and the telomerase activity is enhanced, and the length of the telomere can be maintained without shortening, so that the cells can proliferate and become cancerous. Therefore, telomerase detection and its inhibitors can be used for tumor diagnosis and treatment. Basic Information Specialist classification: Oncology examination classification: immune examination Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Normal value: no Above normal: negative: Normally negative. Positive: Small cell lung cancer has increased telomerase activity in the early stage, and non-small cell lung cancer has more activity changes than in the middle stage. Tips: Keep a normal mindset. Normal value negative. Clinical significance It is suitable for the diagnosis and differential diagnosis of various tumor diseases. Elevation: liver cancer (93.88 OD / 30 μg protein), cancer surrounding tissue (24.09 OD / 30 μg protein). Small cell lung cancer has increased telomerase activity in the early stage, and non-small cell lung cancer has more activity changes than in the middle stage. Positive results may be diseases: precautions for pancreatic cancer and thyroid cancer 1. Pay attention to prevent laboratory contamination and false positive or false negative. 2. Pay attention to remove the polymerase inhibitor contained in the tissue specimen to reduce false negatives. 3. Scintillation analysis technology, ELISA method, in situ hybridization method are more reliable than TRAP method. Inspection process Immediately after the blood samples are collected, they are sent for examination and tumor immunoassay. Detection operation: Genomic DNA was 0.1 μg, buffer containing 50 mmol/L potassium chloride, 10 mmol/LTris-HCl (pH 8.4), 1.5 mmol/L magnesium chloride, 100 μg gelatin, each primer was 0.25 μmol/L; dATP, dCTP, dGTP The dTIP was 200 μmol/L each, the DNA polymerase was 2.5 U, and the final volume was 100 μl. Add a few drops of liquid paraffin to prevent evaporation. Reaction cycle: 1 Denaturation: 90 ° C for 30-60 s, annealing temperature of 2 primers and template: 40-60 ° C 30-60 s, 3 extension: 72 ° C 1-2 min. After repeated cycles of 30 to 40 times, the last 7° 72°C primer extension was terminated for 7 minutes. After removal of the liquid paraffin, the product is available for analysis. After electrophoresis on agarose gel, it was stained with ethidium bromide, and a fluorescent strip of expected amplification length was observed by irradiation with a UV lamp. The product can also be hybridized to a Southern blot or a spot blot with a radiolabeled or non-radiolabeled oligonucleotide probe. It is more convenient to use the PCR automatic instrument. After adding the reaction reagent, DNA template and Taq-DNA polymerase to the test tube, it is put into the adjusted procedure, that is, the required temperature, time, and extension of the respective temperature and time and the number of cycles. The reaction is carried out in an automatic instrument to obtain a satisfactory amplification product. Not suitable for the crowd Those who do not have an indication for examination should not be tested. Adverse reactions and risks 1. Infection: Pay attention to aseptic operation when collecting blood, avoid contamination of water and other parts at the blood collection site to avoid local infection. 2, bleeding: after the blood is given a full compression time, especially coagulopathy, bleeding tendency, to avoid local subcutaneous oozing, bruising and swelling.