SuperScript III CellsDirect cDNA Synthesis Kit from Invitrogen

The abundance of reverse transcriptase (RT) enzymes available in the life sciences market has forced the competitive fine-tuning and enhanced performance of RT enzymes, resulting in a few consistent market leaders. I have personally used Qiagen’s Quantitect reverse transcription kit (reviewed here, Fermentas’ M-MLV reverse transcriptase and Invitrogen’s famous SuperScript reverse transcriptases. Invitrogen’s SuperScript II has been hailed as a pioneering effort at high performance reverse transcription. Its ultrahigh performance mutant variant, SuperScript III, has also consistently performed well in our hands, living up to its expectation as being a superior version of SuperScript II. Recently I’ve been drawn back to the original appeal of the SuperScript RT’s, primarily because of the convenience of Invitrogen’s CellsDirect version of the cDNA synthesis kit. This combined with SuperScript III performance, which I feel is marginally better in terms of yield and full length cDNA generation than the other RT’s I’ve used, has made me a fan of the SuperScript III CellsDirect cDNA synthesis kit.

Although marketed as a kit for mammalian cell lysates, the CellsDirect kit has worked perfectly well in my hands for plant cells. Plant cells grown in liquid culture and treated with the right growth enhancers, stimulators and inhibitors can result in cells with modified cell walls which make them behave similarly to mammalian cells as far as membrane and cell lysis are concerned, hence becoming amenable to direct cDNA strand synthesis. This step is the real appeal of the CellsDirect kit. Instead of isolating RNA from cells and then generating cDNA in a two-step procedure, Invitrogen’s kit can offer a direct one-step cDNA synthesis platform, which saves considerable time and experimental effort. Importantly, it also generates more cDNA since removing an additional RNA extraction step removes the potential RNA loss that is inevitable in the two-step approach. The kit recommends working with samples that contain less than 10,000 cells. I’ve tried with cell dilutions of between 1,000 and 5,000 cells and obtained great cDNA. The kit claims that cDNA synthesis should be attainable from a single cell, and there is no reason to believe this would be unachievable, although I’ve never tried such low cell dilutions. Like all good cDNA synthesis kits, this one is provided with DNase1 which is applied prior to cDNA strand synthesis to limit and hopefully eliminate genomic DNA contamination.

My only complaint with this kit is that I’m always left with the buffer and other things provided yet the RT runs out in those 25 or 100 reactions, and the last time I checked, Invitrogen refused to sell me just the enzyme. I haven’t fully understood why so many suppliers do this, yet several others have moved on and provide the individual components of kits when requested. Another general complaint, which can put customers off purchasing this kit, is a complaint against the company, which is their unnecessarily high delivery charge, which a majority of their competitors have now altogether eliminated by incorporating it into their own corporate costs. This by no means is a criticism of the kit, which on the bench is stellar!