Testing field corn with Cry1Ab/Ac protein test strips is not very feasible

According to a June 4 report in Ningxia Daily, the Pengyang County Agriculture and Animal Husbandry Bureau carried out field testing of genetically modified components in corn. Staff from the Pengyang County Seed Management Station went into the fields and conducted field testing for genetically modified components (insect resistance) in corn varieties sold by seed companies in 6 townships with relatively large planting areas across the county. The specific method was to select large areas of spring-sown corn and collect new corn leaves in the field for testing with Cry1Ab/Ac gene expression protein test strips. Testing of 24 samples from 12 varieties all produced negative results, meaning the tested corn was not genetically modified. (Ningxia Daily)

I saw this report today. Judging from its content, there is basically nothing wrong with it. It is sufficient for publicizing this work in Pengyang County, but as a news report, it seems to lack a bit of rigor. Below I will discuss some of my own views.

For friends who are not very solid in their biology knowledge, it may be unclear what the Cry1Ab/Ac gene is, but if we mention another way of describing it, everyone should be clearer: BT, yes, it is the insect-resistance gene in genetically modified insect-resistant cotton.

Can detecting the expression of Cry1Ab/Ac protein determine whether a crop is genetically modified? The answer is yes, provided that if the protein really can be detected, then a conclusion can be drawn: the corn is genetically modified corn. But if it is absent, it still cannot necessarily be determined that the corn is non-genetically modified. In genetically modified experiments, many genes are introduced, and the ones currently used are by no means limited to insect resistance alone. In other words, if the corn tests negative, it only shows that the corn has not had an insect-resistance gene introduced; it does not mean it is definitely non-genetically modified.

There seems to be another problem in this report: no control was set up in the testing process! This can be said to be a fundamental error. From the report, everyone should also be able to see that all 24 samples showed negative results, meaning no insect-resistance protein was detected. I have every reason to suspect whether the genetically modified test strips had expired and whether they were effective. In any experiment, an experiment lacking a control lacks persuasiveness. I do not know whether it is because Pengyang County really had a loophole when designing the experiment or because this step was omitted in the report!

However, this may seem a bit nitpicky here, but as a provincial-level news media outlet, the above report content seems somewhat inappropriate. As news media, the reach is very large, and the information they convey directly guides the direction of public opinion. Many of the public's misunderstandings about genetically modified organisms to this day are also due to media passing on misinformation, and even news articles like genetically modified organisms causing mice to become sterile can pass review and be published. This is worth reflecting on regarding the current media environment!