The gene chip hybridization buffer is out of stock. What domestic alternative reagents can be used?

Domestic hybridization buffer can be used as a substitute, but it cannot be directly adopted for the entire batch. First, perform a small-scale parallel validation: take the same batch of rice RNA and the same batch of chips, use the original manufacturer's buffer for half and the domestic buffer for the other half, and compare the scan background value, number of detected genes, CV of replicate probes, and overlap rate of differentially expressed genes. The signal dynamic range of rice chips is wide, and elevated background is often related to insufficient blocking or excessively high SDS concentration. It is recommended to choose a domestic manufacturer with cases involving plant chips and require reports on buffer pH, conductivity, and RNase-free testing. If the small-scale test results show a background more than 30% higher or a significant decrease in detection rate, do not force the switch; it is better to borrow original manufacturer's product from nearby laboratories.

Hybridization buffer, blocking agent, and wash solution should preferably be replaced step by step, not all at once. Hybridization buffer is the most critical, containing formamide and dextran sulfate; slight differences in viscosity, pH, and ionic strength can affect hybridization rate and background. If the blocking agent is intended to block nonspecific sites, pay attention to protein composition and molecular weight when switching to domestic products, as this may introduce additional fluorescence background. Wash solution is relatively generic; many domestic wash solutions can be used as long as they are RNase-free and consistent with the original in pH and SSC concentration. It is recommended to first replace only the hybridization buffer with a domestic product while still using the original blocking agent and wash solution; if the small-scale test passes, then gradually replace the wash solution. At all times, keep the original empty bottles and instructions for tracing composition.

A two-month stockout will indeed delay the schedule. Several approaches can be pursued simultaneously: First, contact the distributor to see whether there is inventory in other regions, same-model product in smaller aliquots, or short-dated lots; second, ask nearby universities or service companies whether they have original-manufacturer buffer available to lend or to purchase in a one-week supply; third, use domestic trial samples for parallel validation. If domestic manufacturers are willing to provide trial samples and quality control reports, the communication cost will be much lower. Self-prepared buffer can also serve as an emergency alternative, but reagent purity, filter sterilization, and pH must be strictly controlled, and the risk is relatively high for those without preparation experience. Finally, regardless of which alternative is chosen, retain one lot of original-manufacturer buffer as a control so that if subsequent data become abnormal, it can be investigated whether the issue is related to switching buffers.