choosing real-time PCR machine - (Mar/06/2008 )
Would greatly appreciate any help in comparing StepOne (ABI) and Chromo4 (Bio-Rad) systems. Pros, cons, personal opinions, gut feelings - everything is relevant.
Thank you very much in advance!
Which StepOne you consider, 48-well or 96-well (StepOne Plus)?
I'd go for ABI. It's a leader in the field of real-time unlike Bio-Rad and Chromo is just an upgrade to a normal cycler. MJ (now BioRad) is a classic in PCR but real-time is more than that.
It's about solutions, software and much more.
Didn't tried any of those, but considered StepOne last year among LC480. I've seen the machine (installation of a first one in our country) and the software. By that time they only recently announced 48-well StepOne and that was problem for us, because 48 was too little.
Also if you can contact local representatives to send you a demo machine to try, that's maybe the best way to choose. To see if it fits your applications. Try it, try software and see.
But if I had to choose now, we would probably have a StepOne Plus in our lab now instead of LC480, and LC is more than double in prize!
StepOnePlus also have a new type of block, where you can have six different annealing temperatures, that could be usefull for someone.
And StepOne can be standalone, without a computer, if you don't need one or don't have lab space, starting runs by from your computer by network and so on. I basically don't see any advantages of Chromo, maybe just the prize (not sure) and then you have to decide if Chromo would be enough.
They have the same basic characteristics:
- 4 colors to detect
- both have moving detectors
- 96 wells
- both are small (+ StepOne can be without computer)
ABI has a color compensation algorithm, don't know about Chromo.
It's also considered better in things like temperature stability, uniformity by some.
ABI has a cool new software, don't know about Chromo.
Chromo can have a gradient but StepOne have six different annealings on one plate.
StepOne is a brand new, Chromo4 has some age. (can be both advantage and disadvantage)
Chromo can be cheaper if you already have a PTC-200 base, you just buy an upgrade.
I'd favor StepOne that's for sure. It has incredibly easy and user-friendly setup.
(and no, I'm not affiliated with ABI, their bureaucracy is sometimes a pin in the ass 
)
(and yes, I really regret now having one of those StepOnes in our lab, it's a neat, quiet, small guy 
)
We've recently bought an ABI 7500, no experience at all with the StepOne, but ABI are good and the tech support is great!!!!
Personally had very bad experience with Chromo. Had a Chromo4 in my old lab (when it was MJ, but I doubt theyv'e changed anything but the name), main problem completely unreproducible results, same reaction in 96 wells will very proably give 96 different results (maybe not that bad, but definitely NOT the same results in all wells) plus tech support is rubbish, at least in the UK.
I'd definitely go for AB, they're definitely lead in the market (that or Roche).
Thank you guys, I really appreciate the help! I am a bit stuck here with the decision - there are nobody with this kind of experience in our lab and I am not much of an expert either. 
The machines in question appear to be the only alternatives as our price limit on that is about 20 thousand euro. StepOne that we can offer is not the PLUS, just basic 48-well model with 3 filters, while Chromo4 is 96-well with 4 filters.
Uneven T in the block is a big thing, true...
Hmm, them make an important decision on how big amounts of samples do you want to run. 96 may seem a lot, but when you run in triplicates, and want to do standard curve as well.. it's not much space. But as far as I know, there will be option to upgrade StepOne to StepOne Plus in the future, so if you want to start small, and later move to bigger quantities, this can do it.
Anyway definitelly contact sale guys from both companies and tell them you can't decide. They will try to make you decide for them (and make stories about other comapanies, funny), maybe even try to push the prize lower, when you could consider using their chemistry as well. Let them make efforts, and
almost a doctor: Well, I've heard Roche guys to tell, that Roche and ABI are the best, but ABI guys tells they're the best and Roche only wannna be 
have you looked eppendorf or stratagene, both have pretty nice machines too (not sure about prices though). Problem I found with Chromo wasn't Temp related but detection, as all my samples where positive on agarose gel, but not all of them showed fluorescence. Something to do with the optics I found out later (from the Stratagene rep) but cant remember the details.
These are more expensive... I talked to the most of the more or less known companies and collected their offers. Basically, the choice is between the two models I am asking about. If StepOne had 96 wells, there would be no question. As for our needs, I am not sure what they are in terms of the workflow 
. Does it always create a lot of problems if you split your samples (=replicates) between the runs?
. Does it always create a lot of problems if you split your samples (=replicates) between the runs?The first qPCR machine I used was Roche's light cycle, which only allowed 32 samples, so including standards, controls and replicates.... not much. I didnt use to run replicates (no space) instead run each sample 2 or 3 times to confirm the same result was observed. Also, in order to compare samples from different runs I'd have a "reference sample", ie I run a positive sample with all my runs (always same sample), and then refer my results to that sample. Works pretty nice.
It also depends which method you'll be using, as for delta delta Ct you dont need standard so there are more wells available for sample.
I'll definitely go for AB, more reliable and better tech support, 2 very important things. Also they gave us a pretty nice discount, so try that, and discount too on reagents, plus loads of free plates
THANKS 
How about bettwe possibilities for multiplex in Chromo? Are they real?
Hi
I have very limited experience with ABI so I can't really give an opinion on that, but I have been working with the Chromo4 for ~2yrs, and I'm definetely not convinced with it: lack of reproducibility of the results, frequent crashes of the machine, bad assistance from the techs. If you're using a Chromo4, I really recommend using triplicates to feel more confident in your results, while when I was using a LC from Roche, duplicates were more than enough as they were always spot on! (I so miss the LC!)...