How to read the fluorescence quantitative PCR test report
Fluorescence quantitative PCR (polymerase chain reaction) is a molecular detection technology widely used in the fields of medicine, biology and environmental science. With the recent recurrence of epidemics and the increase in health awareness, fluorescence quantitative PCR test reports have become the focus of public attention. This article will provide a structured analysis of how to understand this type of report, and attach relevant data examples.
1. Interpretation of core data of the report
| Project | meaning | normal range |
|---|---|---|
| Ct value | The number of cycles at which viral nucleic acid reaches the detection threshold | ≥40 is negative <35 is positive 35-40 needs to be retested |
| Internal reference gene | Sample quality control (e.g. β-actin) | Ct value≤32 |
| amplification curve | Visualization of reaction progress | S type is an effective reaction |
2. Analysis of recent hotspot correlations
Data from the entire network in the past 10 days shows that discussions related to fluorescence quantitative PCR are mainly concentrated in the following areas:
| Topic classification | Proportion | Typical questions |
| Epidemic prevention and control | 42% | How to judge the result of a double positive test |
| pet diseases | 23% | Interpretation of canine distemper virus detection |
| food safety | 18% | Testing Standards for Genetically Modified Ingredients |
| cancer screening | 17% | Circulating tumor DNA detection threshold |
3. Step-by-step interpretation guide
1.Confirm detection target: The first part of the report will clearly indicate the test items (such as SARS-CoV-2, Epstein-Barr virus, etc.), and the criteria for determining different pathogens may be different.
2.Analyze Ct value: The smaller the value, the higher the viral load. It should be noted that there may be an error range of ±2 between laboratories.
3.Check quality control indicators: The conformity report should contain:
| positive control | Ct value≤30 |
| negative control | No amplification curve |
| standard curve | R²≥0.98 |
4. Answers to typical questions
Q: What does a Ct value of 37 mean?
It needs to be combined with clinical judgment: if the initial screening is positive, it is recommended to retest after 48 hours; if the test is during the recovery period, there may be residual viral fragments.
Q: Are there big differences between different brands of reagents?
The main differences are in the limit of detection (LOD) and primer design, but nationally certified reagents should meet unified quality standards.
5. Expert advice
1. Give priority to laboratories certified by ISO15189
2. Irregular sampling may lead to false negatives
3. Pay attention to the sample transportation temperature (2-8℃) during winter testing.
4. Genetic testing needs to be combined with other clinical indicators for comprehensive judgment.
By systematically mastering the report interpretation methods, the public can understand test results more accurately and avoid unnecessary anxiety caused by misinterpretation. It is recommended to save the original copy of the complete report for reference in subsequent diagnosis and treatment.
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