We are wanting to order a new blood bank heat block.  The one we currently have is not holding temperature well.  We are having to constantly adjust it back to normal range.  We currently have a Thermo Scientific Multi-blok.  Any suggestions for a good replacement that is actually able to hold a temperature?

 

Thanks in advance for the feedback

We use Thermolyne Type 12200 Dry-Bath.  Have rarely had any problems.

 

Brenda Hutson, CLS(ASCP)SBB

Same as Brenda. Had them for years, absolutely no problems.

 

Phil

And you can put the thermometer in a tube, add saline to the top of the well only and then seal with parafilm.  You have to occasionally replace the parafilm and refill the tube, but we have used this method for years and it works very well.

Edited February 24, 201411 yr by carolyn swickard

And you can put the thermometer in a tube, add saline to the top of the well only and then seal with parafilm.  You have to occasionally replace the parafilm and refill the tube, but we have used this method for years and it works very well.

I do a similar thing with a blue coag tube - poke a hole in the top with an arm of a pair of narrow scissors, lube the thermometer up with a little silicon, and insert. If you insert a syringe needle (no barrel) in the stopper while you do this it gives the air displaced by the thermometer somewhere to go and the top will never pop off. Never evaporates, never spills.

I do a similar thing with a blue coag tube - poke a hole in the top with an arm of a pair of narrow scissors, lube the thermometer up with a little silicon, and insert. If you insert a syringe needle (no barrel) in the stopper while you do this it gives the air displaced by the thermometer somewhere to go and the top will never pop off. Never evaporates, never spills.

Genius...never thought of it!

Did anyone else notice that Heat Blocks were listed under Hot Topics! 

 

The last heat blocks I had came equipped with digital temp read outs.  After doing all of the qualification testing to make sure the digital temps were accurate and reliable we only put a thermometer in the heat block when doing the monthly or semiannual (I can't remember which) 4 corner check.  That way we were not breaking off thermometers when reaching across heat blocks for some reason.  Never had any problems with those heat blocks.  Sorry but I can not remember the brand.

Well, I for one hadn't noticed John.

Simply LOVE your sense of humour!!!!!!!!

Does anyone have a source for a short (approx.4 inch) non-mercury thermometer for heating block?

I would ask my Fisher or Cardinal sales rep. Let them do the legwork. It's not as easy as it used to be to grab a catalog and thumb through it.

S/P Dry Bath/Block Heater Thermometers come in a smaller tube (a microcentrifuge tube) which makes it a little shorter (total is 125mm length).

Also, it should be noted that not all heat blocks have digital read-outs so would need to document temps. daily (and I know of 1 occassions where a heat block was accidentally turned off at some point; one of the types that had that flip switch on the front) and the Tech. doing testing did not notice it. She called an Antibody Screen on an ER patient, Negative; but turned out they had an Anti-Fyb.....so not a bad "habit" to get into of looking at your thermometer (or digital reading) when placing something in the heat block.

We also have a place on our Temperature Log to document that we move the thermometer 1 space to the right every day so we are making sure each well is working (may be over-kill but is not a difficult process; espeically if on yor Log).

Brenda Hutson

After posting it occurred to me I might want to find a spare, so I emailed my rep and just got a quote for the thermometer Brenda mentions above. Here are the specs and Fisher catalog #:

 

13-201-914

Thermometers, Non-Mercury; H-B Instrument; Fisherbrand Dry Block/Incubator; Durac Plus; Range: 18/60C; Divs.: 0.5C; Accuracy: +/- 0.5C;Organic fill;PFA coated;35mm immers;125mm L;Calibra traceable to NIST;Calibra report w corrections

There is a thermometer available from Cardinal that is coated with Teflon(?) to make it more durable. The info on the thermometer is Cat. No. 715 S Imm 35 mm +23+57C INCU-BLOCK PG ERTCE. Highly recommend this one - we used to break 1-2 a year reaching across the heat block. We haven't broken one of these and we've been using them for 4 or 5 years.

I once had a gel heat block come unplugged at the back of the unit from people adjusting it forward with the cord caught on something. Fortunately we caught it before any positive screens were run (we repeated affected tests).  Almost worth having an alarm system considering the negative patient impact if not caught.  Fortunately it is rare.

I once had a gel heat block come unplugged at the back of the unit from people adjusting it forward with the cord caught on something. Fortunately we caught it before any positive screens were run (we repeated affected tests).  Almost worth having an alarm system considering the negative patient impact if not caught.  Fortunately it is rare.

I was taught a bit ago (well, in 1972) to touch the top of the heat block as you put your tubes in. Not quite a thermometer, but at least you know it's plugged in.

Recently purchased a Labnet Accublock Dry Bath from Market Lab Inc. You can get different blocks for 10 or 12 mm tubes. It has digital setting and digital readout. We validated with an external thermometer in multiple wells over multiple days. Maintains temp within +/- 0.1 deg C. It's nice having the digital display so you can tell that it has not been unplugged or turned off.

Owen Bain

And you can put the thermometer in a tube, add saline to the top of the well only and then seal with parafilm. You have to occasionally replace the parafilm and refill the tube, but we have used this method for years and it works very well.

. Is this a plastic or glass blue top tube?

You might want to check the specifications.  We had the analog version and couldn't validate the heat blocks and then later discovered that the analog control has a 37°C: ±3.5° range.  So, if it is set to 37C, you could get a temp anywhere from 33.5C to 40.5C!!  We had to return them and buy digital models.