The top ten imported reagents are too expensive. What is the actual effect of domestic substitution?

Do not switch directly before replacement; first perform a complete parallel validation. Take the same batch of template, perform PCR with imported enzyme and domestic enzyme separately, run a gel to check product yield and specificity, and after cloning with high-fidelity enzyme, send for sequencing to compare mutation rates. For restriction enzymes, perform restriction completeness experiments: digest 1 μg plasmid with 1 U and 5 U respectively, for 1 hour and overnight, to check for star activity or degradation. Also ask the supplier for the enzyme activity definition and batch-to-batch enzyme activity CV data; some domestic manufacturers can provide this, but you need to actively request it. After validation passes, switch routine experiments to domestic enzymes, and use imported enzymes for rechecking critical samples or data intended for publication; this minimizes risk.

The advantages of domestic alternatives lie in delivery time and after-sales service. For manufacturers such as Vazyme, TransGen, and Yeasen, technical support responds relatively quickly. When encountering nonspecific amplification or abnormal restriction digestion, you can send the data and conditions to them for analysis, and the response speed is generally faster than that of the original imported manufacturers. However, if the purchase channel is a distributor rather than the manufacturer, technical support may be compromised. It is recommended to choose manufacturer-direct sales or a first-tier distributor for the first purchase and confirm whether batch documents can be provided. Among the top ten imported companies, not all enzymes are irreplaceable; some commonly used enzymes are already very mature domestically. However, for key experiments or special modifications, it is advisable to retain imported products. During the switching process, keep at least one tube of imported enzyme as a control to avoid batch issues affecting the entire project.

The usage of 20 reactions per month is not significant. Buying small packages may result in high unit prices, while buying large packages may result in decreased enzyme activity over time. Improper packaging can lead to repeated freeze-thaw inactivation. Domestic enzymes generally come in small packages for testing, and it is recommended to apply for a trial package for validation first. If the verification is successful, purchase according to the three-month usage to avoid stockpiling. Some domestic brands have a pre mixed liquid form, which is convenient and reduces operational errors, but the unit price is slightly higher and can be compared based on single cost. The goal of importing less than half is easily achieved on conventional PCR enzymes, while restriction endonucleases depend on the specific model, and rare enzymes may have limited reduction. Ask if there are any promotions or research collaboration prices.

I have tried several domestic alternatives for restriction endonucleases and PCR enzymes, and conventional experiments can indeed save a lot. Endonucleases that have been used for nearshore and full gold have no significant difference in the efficiency of commonly used site cleavage and import ratio. However, when encountering methylation sensitive or rare site cleavage, it is still necessary to test the star activity by oneself. The PCR enzyme has been used with regular Taq from Novozymes and Yisheng, as well as high fidelity. The amplification yield and fidelity are sufficient for daily use. It is recommended to send several clones of high fidelity products for sequencing to confirm the mutation rate. In terms of batch stability, I usually run the same batch of samples in parallel with the old and new batches to confirm that there is no significant drift in Ct values or strip brightness before using them in batches. The single cost can be reduced to less than half of the import cost.