OneScript® Plus Reverse Transcriptase

What it means: Synthesis Temp is the temperature range at which the enzyme carries out reverse transcription. At 50–55°C this mutant runs above the ~42°C ceiling of wild-type M-MLV.

Why it matters:

• Running hot melts hairpins and GC-rich structure that otherwise stall the enzyme and truncate cDNA.
• Higher temperature increases priming stringency, so less non-specific cDNA carries into the downstream PCR.
• The raised working range is what allows the short 10–15 minute reaction without sacrificing yield.

How to interpret here: Use the lower end for routine templates and the top of the range for GC-rich or structured RNA. Check that the primer Tm supports the temperature chosen — oligo-dT priming is the first thing to suffer.

Tip: If long transcripts come back truncated, raise the temperature within the range before increasing enzyme or extending time.

What it means: RNase H Activity is the enzyme's ability to degrade the RNA strand of an RNA:DNA hybrid. Wild-type M-MLV carries it; this mutant has it genetically abolished, so the template survives as cDNA is built along it.

Why it matters:

• An intact template lets the enzyme continue to the 5′ end, which is what makes full-length and long cDNA achievable.
• Removing RNase H also improves yield from low-input RNA, where premature template destruction is costly.
• The mutation is what confers the added thermal stability, so reduced RNase H and the raised working temperature come together.

How to interpret here: For 5′-end recovery, long transcripts, or full-length cloning, reduced RNase H is the property that matters most. Short qPCR amplicons benefit less.

Tip: If a downstream step needs the RNA removed, add RNase H separately after cDNA synthesis is complete.

What it means: Buffer Included describes the reaction buffer supplied with the enzyme. This product ships with 400 µl of 5X RT Buffer, matched to the 100-reaction enzyme pack.

Why it matters:

• Reverse transcriptases are more buffer-sensitive than DNA polymerases — salt and reducing conditions strongly affect processivity.
• The matched buffer removes composition as a variable when troubleshooting a failed cDNA synthesis.
• Because this enzyme is formulated with RNaseOFF (Cat. No. G138), the supplied buffer is also the condition under which that inhibitor was validated.

How to interpret here: Dilute the 5X RT Buffer five-fold — 4 µl in a 20 µl reaction. Do not substitute a buffer from another supplier's RT kit.

Tip: Thaw and mix the buffer completely before pipetting; components settle during frozen storage.

What it means: Max cDNA Length is the longest first-strand product the enzyme can reliably synthesise from a single template. Here it is 12 kb, well beyond the 1–2 kb that wild-type M-MLV typically manages before falling off.

Why it matters:

• Processivity sets whether a full-length transcript is captured or only its 3′ portion — a truncated cDNA silently loses the 5′ end of the message.
• Long-range RT is what makes full-length cloning, isoform discrimination and 5′-end analysis possible from a single reaction.
• The 12 kb figure assumes intact input; degraded RNA caps the achievable length regardless of the enzyme.

How to interpret here: For targets under a few kb this is not the deciding property. It matters when the transcript is long, when the 5′ end must be recovered, or when a full-length clone is the goal.

Tip: abm's product page quotes 12 kb in the description and specification table but 15 kb in one marketing bullet; BioHippo uses 12 kb as the stated figure. Extend the incubation rather than raising enzyme when a long target comes back short.