I would like to summarize the responses I got to my posting on the choice of
automatic DNA sequencer.
1. ABI 377, especially cost-effective with XL plus 96-well upgrades (slab gel).
This instrument is very popular and this fact explains why I got many comments
BigDye terminator technology gives high sensitivity and good routine reads up
to 800 bases, especially when 48 cm gels are used. Single tube reactions are
very convenient. Base calling is generally very good and easy to proofread.
Casting gels may be a pain. Nevertheless, when you consider that from one gel
you may read about 76,800 bases, this problem is really minimal. Most
respondents criticized ABI support and sales personnel noting their ignorance,
lack of timely response to service calls, and even arrogance.
Conclusions: This machine is definitely the best buy. Even if ABI will not
help you with your problems, you will get great help from a nearby lab or from
posting questions on the Net. The installed base of this instrument and
reliability is its biggest advantage. You may place an order for this machine
without bothering to ask for a demo.
2. ABI 373 and 373A (slab gel).
There are still some people that use these instruments. They usually love
them; however, they would like to switch to the ABI 377 sequencer because of
higher throughput and sensitivity.
3. LiCor (slab gel).
This machine has very few, albeit vocal, supporters. Users report longer reads
per reaction than for ABI 377 (up to 1,200 bases). Reagents may be cheap;
however, you may use only dye primers and you will have to run four reactions
per template, each for every terminator. Primer walking with LiCor is
therefore more expensive than with the ABI 377. The installed base is very,
very small; however, strong showing of this instrument in the recent ABRF test
may make LiCor a viable alternative to ABI 377.
Conclusion: Get a demo machine first.
4. ABI 310 (single capillary).
This machine has some enthusiastic users; however, it performed very poorly in
the recent ABRF test. The reads are shorter (450 bases) than for top
instruments and the throughput is rather low. Basecalling is not as accurate
as on the ABI 377.
Conclusion: All things considered, this machine can be only recommended to
people that are extremely allergic to pouring gels.
5. Beckman CQ 2000 (eight multiplexed capillaries).
I got only negative comments about this instrument. The few people that have
seen a demo or tested this instrument think that at some time in the future it
may be a viable alternative to the ABI 377. Currently, both the chemistry and
software needs a lot of improvement.
Conclusion: Ask for a demo and provide Beckman with your input. ABI needs a
6. Pharmacia Alf (slab gel).
Bad chemistry, poor sensitivity, bad base calling, and very poor support.
Conclusion: If you are using this instrument, start looking for a replacement.
7. Visible Genetics Blaster, Clipper, and LongRange Tower (slab gel)
I got a handful of very negative comments about chemistry, support, software,
Conclusion: Don't ask for a demo.
8. ABI 3700 (96 multiplexed capillaries)
Possibly the best machine for genome sequencing labs with strong allergies
towards pouring gels. Expensive. May have a lot of "beta release" problems.
Conclusions: Watch postings of ABI 3700 users on the Net.
In article <7ld8u8$j0d at net.bio.net>, john_q_barlow at hotmail.com says...
>I posted twice messages inviting comments from users
>of DNA sequencers made by Visible Genetics, Inc. (Visgen).
>They make MicroGene Blaster, MicroGene Clipper, and the Long-Read Tower
>automatic DNA sequencers.
>>So far, I received only negative comments from users of these machines
>or from people that saw a demo. The only (biased) positive comments
>were from Visible Genetics salespeople or from people that have
>a financial stake in this company. Visible Genetics seems to be very active
>in the venture capital and stock market.
>>As these opinions may be biased, I would appreciate comments from
>people that have not seen my previous postings. We are frequently
>asked for advise on what DNA sequencing system to purchase and would like
>to have as many comments as possible.
>>So far, the most popular choices of my responders were:
>1. ABI 377 with the XL upgrade
>2. ABI 310
>4. Beckman CQ 2000
>>Personally, I think that in about a year or so the Beckman
>CQ 2000 system will mature and may go to position 2 or 1.
>It seems that there are very few users of the LiCor system that
>bothered to answer my question. They seem to be quite satisfied.
>The new ABI 3700 system may be technologically superior, but it
>is possibly too expensive for labs that do not engage in genome
>>Thanks in advance,