For HBV DNA quantitative detection molecular diagnostic kits, is it more reliable to choose domestic or imported ones?

Imported products offer a wide linear range and small inter-batch variation, but have long lead times and high cold-chain costs, posing a significant risk of reagent supply interruption for primary-level departments. Among domestic HBV quantitative reagents that have obtained certification, manufacturers such as Sansure and Da An Gene have larger user bases, but I would not rely solely on brand reputation. It is advisable to require suppliers to provide a list of tertiary hospital users in the local region and conduct on-site inquiries about their operational experience. Do not focus on advertised sensitivity; instead, check the LoD and linear range specified in the instructions for use. If the budget is limited, domestic products can be adopted first, but sufficient time must be reserved for validation during initial hospital introduction.

Our laboratory has compared them. When low copy numbers are below 100 IU/mL, imported reagents do indeed show more stable linearity and repeatability, but top domestic brands differ little above 100 IU/mL and for common genotypes, and can meet routine clinical monitoring needs. If the budget is limited, we recommend choosing domestic products, but you must perform your own validation: use WHO standards or commercial quantitative reference materials for gradient dilution, focusing on the detection rate and CV at 20–100 IU/mL. For lot-to-lot variation, run parallel tests on at least 3 consecutive lots; do not rely solely on the manufacturer's advertised sensitivity.

The impact of the extraction step on HBV DNA quantification is no less significant than that of amplification. If you use column-based extraction, it is best to keep the same brand of extraction kit or at least use the extraction system specified in its instructions; otherwise, low-value results tend to drift. Mixing and matching is not impossible, but you need to perform spike-and-recovery yourself: spike known-concentration serum, extract, calculate the recovery rate, and test repeatability with low-value samples. Serum samples must be fully lysed, and the elution volume should not be changed arbitrarily. We previously used domestic amplification with imported extraction and the results were usable, but troubleshooting was troublesome when problems arose.