Will buying enzymes and primers separately from the reverse transcription kit reduce their universality?

Before changing the system, divide the same batch of RNA into three groups: the original one-step kit, the new enzyme with random primers, and the new enzyme with oligo dT mixture. Perform target or internal reference qPCR simultaneously and compare Ct values with negative controls. If Ct deviation is significant, first check the buffer ion conditions, primer final concentration, and reverse transcription temperature, and do not immediately determine enzyme incompatibility.

For viral RNA detection, if the target is an RNA virus, it is recommended to use a mixture of random hexamers and oligo dT to improve coverage uniformity; if only specific genes are to be detected, gene-specific primers can also be used for reverse transcription, but their universality is inferior to the random/oligo dT combination. When primers from different brands meet purity standards, there is generally no matching issue.

When inquiring about 50-reaction small-pack sizes, don't just look at the list price—ask clearly whether RNase inhibitor is included and how many microliters per reaction are counted per use. Domestic reverse transcriptase 50-reaction sizes are usually budget-friendly, but it is advisable to first request a trial pack or small sample for validation. During the switch, keep the original one-step kit as a control to avoid test samples being affected by the system change.

In the two-step method, reverse transcriptase, buffer, and primers can usually be paired across brands, with the key being the use of 5 x buffer for reverse transcriptase. Purchasing primers separately has little impact. Random hexamers or oligo dT have high universality, and it is recommended to choose H-minus M-MLV. 500ng throat swab RNA is a routine input amount, and cDNA stability mainly depends on RNA quality and operation, rather than having to be of the same brand as primers.