The logic behind Wanfu and Lizhu's new crown test kit being returned by India

First, it is not necessarily a quality problem;April 27, the Indian Medical Research Council found that the new coronavirus antibody rapid detection kit imported from China was not performing well and asked for its returnApril 28, the Chinese Embassy in India responded to the matter;source: Guangzhou Wanfu Biotechnology Co., Ltdofficial websiterelated enterprises two, one is Guangzhou Wanfu, the other is Zhuhai Lizhu reagentsSince the specifications of the two products were not available from public sources, more information can only be obtained from the official website of the FDAsource: the official website of the Drug Administrationthis is the colloidal gold kit of Lizhu reagent, storage temperature 2-30 degrees C, so the temperature change of the transport process should not be the focusBased on past experience, assuming that a kit is valid for 12 months and saved at 2-8 degrees C, the product will be sampled before the factory, and a 37-c6-day acceleration stability will be experienced to theoretically simulate the detection results after 12 months at 2-8 degrees CEven if exported, there should not be such a long, harsh hot environment on the roadMoreover, it is a 2-30 oC storage kit, so temperature should not be the focuswe don't know exactly which indicators are bothering the two kits, so we can only do regular analysis." So what are the common problems with test kits?1 false negativethat is a positive sample, which was not detected during the testThis may be due to insufficient sensitivity, that is, the detection limit, the sample of the substance to be tested content is too small to cause the expected reaction of the test reagent2 false-positive may be a similar to the object to be tested, or it may be interference with other chemical agents in the environment In general, specificity is not good enough to cause false positives For example, if you hear a room moving, you decide that there must be someone in the room At this point you use the sound as an evaluation indicator to judge, but open the room and find that there is a cat inside, which is equivalent to false positive Explain that your evaluation indicator has a problem and cannot be judged by a simple voice If you use "whether the sound is the language of humans" to judge, the rate of misjudgment will be much lower This "human language" is equivalent to specificity and is used to assess the specificity of the object to be tested is there a test item to test false negative, false positive? there are to detect AIDS enzyme-linked immune kit as an example, there is a key project is over-the-quality serum disk It may be true to talk about a paragraph here A banknote checker has a rating, is to take a variety of counterfeit money to check the machine, see how high the simulation can pass, a factory check the accuracy of the note check ereverity 100 percent, all counterfeit money has been found out People puzzled, after the enterprise leak, "the checker's alarm set to all banknotes are considered as counterfeit money alarm", so that counterfeit money naturally all the alarm Of course it's a paragraph from this paragraph we can see that if there are only positive samples in the serum disk, then the enterprise may also be like the money machine enterprises to do so So there are not only positive samples in the QC serum disk, but also negative samples Companies are required to test positive samples and to be able to identify negative samples In this way, enterprises in order to protect the positive pass rate, will certainly increase the test limit, and too high the test limit will increase the probability of false positive, so the specificity must be very high in order to ensure that positive, negative test is it possible to be positive if a positive sample of an enzyme-linked immunoassay is positive? Not Further, more accurate testing reagents or methods are used to determine Of course, PCR is very precise, but it is also very expensive So there will be other ways to diagnose it Syphilis, for example, uses TPPA, a coagulation test, to make the final judgment and colloidal gold detection, because of its convenience and timeliness, will certainly lose part of the accuracy For example, AIDS antibody testing, colloidal gold ten minutes out of results, enzyme-linked immune test to a morning to produce results, and another can clear subtype classification of the kit needs to be overnight It's not that it's cheap or not good, but if you save time and money, you're bound to lose something else Therefore, in the kit will be marked "cannot be used as a new coronavirus infection of pneumonia diagnosis and exclusion of the basis." This is not to shirk responsibility, but to inform the test ingres stoking risk colloidal gold is currently the closest to the public is the pregnancy test paper, is ordinary people can judge the results And the new coronal pneumonia colloidal gold kit, clear must be a medical institution to do What does that mean? Colloid gold for the detection of new coronavirus also need to have a professional background, any need to have a professional background of the operation, there will be higher human factors interference In particular, colloidal gold, unlike the enzyme-linked immune method can read out specific values, colloidal gold results only look at the color depth, human factors interference is largely avoid the fate embassy's answer to the reporter's question, on the one hand, for the enterprise to speak out, to India and enterprises a channel of communication, on the other hand, is also to avoid other domestic reagents have adverse effects After all, the demand of foreign testing market, there can be no flashbacks picture source: Dongxing Securities this Dongxing Securities data show that the detection of reagents overseas market gap is huge The country has suffered from an early outbreak, whether for economic or other considerations, should seize this gap In particular, can not be put on a smudge hat, timely proof, perhaps the most need for enterprises to do Reference: Professor Li Jinming: Answers to The Hot Questions for Clinical Applications of New Coronary Nucleic Acids and Antibody Testing