Frequently asked questions about the use of Lab Armor Beads in laboratory water baths.

1. Lab Armor FAQ – June 2012
1. Are Lab Armor Beads packaged as ready-for-use?
Yes, Lab Armor Beads arrive in a sealed container ready to add to your thermal
instrument.
2. How much Lab Armor Beads do I need?
Unlike water, Lab Armor Beads don’t evaporate and therefore helps protect against
instrument overheating and burnout. But, like water, it is important to add a sufficient
volume to your bath to ensure safe operation. An insufficient volume can cause
inaccurate thermostat readings, which can result in continuous heating of the bath. Most
water baths operate properly when filled to 80% full. Use the Lab Armor Beads
calculator on the Lab Armor website to help you determine the optimal volume for your
water bath.
3. How long can I use Lab Armor Beads under normal conditions?
Under normal conditions, Lab Armor Beads should last the life of the water bath. If
used incorrectly, the surfaces of Lab Armor Beads can become damaged, resulting in a
loss of fluidity of the bath, but not in thermal performance. We recommend that you
avoid strong detergents, acids and bases. Bleach, for instance, may tarnish the surface
of the Lab Armor Beads reducing its fluidity and overall performance.
4. Can I autoclave Lab Armor Beads?
We recommend that you avoid autoclaving Lab Armor Beads, unless you autoclave in a
sealed, moisture-proof container. The high temperature steam can cause the surface of
the Beads to become sticky, reducing its fluidity and overall performance. Should you
need to disinfect, spray the Beads with 70% ethanol and mix.
5. Can Lab Armor Beads be used in a standard heat block?
Yes, Lab Armor Beads are compatible with all standard heat blocks. You will no longer
need to buy a new aluminum block when a vessel doesn’t fit. For optimal performance,
use a Lab Armor Bead Block with Beads in your heat block.
6. What if something is spilled into the Lab Armor Beads?
Lab Armor Beads may be washed with dish detergent and water then sprayed with 70%
ethanol if necessary. Most importantly, be sure to completely dry the Beads before
adding back to the water bath, because a combination of heat and water can tarnish the
beads. You can use a mesh strainer to wash and dry. A nylon <1/4" mesh bag works
well, such as a camping stuff sack that you can find at a camping supply store.

2. 7. Do I need to use the water bath instrument cover with Lab Armor Beads?
Yes, it is best practice to use the cover whenever possible. The cover allows maximum
temperature range and helps maintain better temperature uniformity. In general, without
the cover in place, the surface of the Beads will be slightly cooler due to the movement
of cooler air over the bath.
8. Do temperature gradients exist in a water bath?
Yes, all water baths have hot spots and temperature gradients. The extent of the
gradient depends on the design of the water bath. In some baths, for instance, the
heating element is small or is not centrally located. In others, the heating element
expands the entire surface of the bath providing a more uniform heating capacity. Lab
Armor Beads perform like water and the temperature gradient in a standard water bath
is very similar as well, usually +/- 2.5ºC. However, for higher precision applications, the
Lab Armor Bead Bath performs at +/- 1.0ºC. One advantage of Beads is that a sample
vessel can be completely submerged in the beads, eliminating exposure to surrounding
air temperature.
9. Is my water bath compatible with Lab Armor Beads?
Lab Armor Beads can be used with just about any water bath. However, like water, the
performance of the thermal media depends on the design of the bath and the location of
the heating element. With water, for example, "hot spots" occur in areas of proximity to
the heating element. Some elements are exposed on the bottom of the bath and others
are recessed. Some baths are deep and others are shallow. In a bath with the element
located in the center, water and Beads generally produce a temperature gradient of +/-
0.25 -0.75 ºC per inch in all directions from the middle of the bath. So, depending on the
size and location of the element, as well as the dimensions of your bath you can gauge
the performance of Beads in your bath.
10. How do I keep my Lab Armor Beads shiny and fluid?
Normal amounts of precipitation on refrigerated bottles and vials are NOT harmful.
However, avoid exposure to a combination of heat and water or reactive chemicals that
oxidized the surface of the Beads. Chemically accelerated oxidation reduces the Bead's
shine and more importantly, its fluidity. In general, Beads can last for many years if kept
relatively dry and clean. It can even out-live your water bath.
11. Are Lab Armor Beads compatible with most commercially available baths?
Water baths from several major US manufacturers, including the Thermo Fisher & VWR
baths have been tested with Beads. Data shows that most baths are compatible, no
matter their age. An exposed or recessed thermocouple does not seem to affect the
performance of the Beads. However, the location and configuration of the heating
element can make a difference in heating uniformity. Most of the water bath design
problems affecting Bath Armor performance, also affect the thermal performance of
water. Circulating water baths are generally incompatible with Beads.

3. 12. How do Lab Armor Beads perform under high or low temperatures?
Beads have been tested using various water bath models at a range of temperatures. In
most traditional water baths, the further the set temperature is from ambient
temperature, the greater the thermal gradient will be in the bath. Therefore, at an
operating temperature of 37ºC to 42ºC, the thermal gradient in a common water bath is
typically +/-1-3ºC, whereas at 55-65ºC it is closer to +/-3-8ºC depending on the design
of the bath and the amount of Lab Armor Beads used.
For applications that require greater temperature control, a Lab Armor Bead Bath can
be used. Bead Bath is designed specifically for use with beads, and therefore provides
more consistent, uniform temperatures throughout the bath compared to traditional
water baths. Thermal uniformity is +/- 0.5ºC at 37ºC
13. Are there ways to speed up the heating process with Lab Armor Beads?
Incubating:
Beads warm 1.25-2.5X slower than water, depending on the volume of the vessel. But,
there are ways to compensate for this:
• Raise the temperature of Beads
• To avoid over-heating, validate the adjusted protocol
• Keep the conditions constant from experiment to experiment
For example, to raise the temperature of a typical 500 ml bottle of cell culture media
from 4ºC to approximately 37ºC in 30 minutes, traditionally, a 37ºC water bath is used.
To accomplish the same results using Beads, the bottle can be submerged in 50ºC
Beads for the same 30 minutes, then pulled out and placed onto the surface of Beads.
The Bottle of media will remain at 37ºC +/- 2ºC for up to 6 hours until use.
Thawing:
When a frozen vessel is placed into the bath, the beads surrounding the bottle become
temporarily cool. And if the vessel is large enough, just like a water bath, the overall
temperature of the bath will decrease slightly below the set point and trigger the bath to
begin heating. The cool areas surrounding the bottle will slowly warm up until the bottle
reaches the set temperature. Although similar gradients are produced in water baths, in
general, the whole bath cools down and re-warms without obvious gradients because of
normal disturbances and stirrings, as well as natural thermal circulation of water.
Instead of always stirring the bead bath, customers can most likely solve their problem
with a simple change in protocol. By allowing frozen vessels to thaw overnight in the
refrigerator to 4ºC before placing it in the bath, it will warm quickly in the bead bath and
will not contribute greatly to cooling the bath and disturbing the temperature gradient.

4. 14. Besides keeping the bath cleaner, how do Beads protect samples better than
water?
• Eliminates the possibility of water wicking into the sample
• Eliminates cross-contamination from water dripping off a vessel onto other items
on the bench when removing vessel from the bath
• If the bath is accidentally turned off or loses power, Beads maintains temperature
up to 5 times longer than water offering better protection for the incubating
sample.
• While thawing large vessels, surrounding Beads become cooler rather than the
entire bath.
15. Is an air-jacketed water bath compatible with Lab Armor Beads?
In general, air-jacketed baths provide better overall heat distribution and temperature
gradients. The air jacket that surrounds the tub portion of the bath allows the heated air
generated by the heat element at the base of the tub to also warm the walls of the tub.
Since bead baths primarily rely on heat conduction (heat transfer by contact), baths with
heated walls transfer heat to the beads from 4 directions. Baths without air jackets less
efficiently heat the beads from the bottom only.
There is another potential design problem with some non-air-jacketed baths. If the
bath's heating element is not recessed below the tub, but it is instead fixed to the tub by
metal-to-metal contact, the base of the bath can become very hot in areas where
contact is made. This produces hot spots on the bottom, which results in uneven
gradients in the bath. Small sized heating elements that only cover a small portion of the
base of the tub makes this problem worse. Such baths produce hot spots even when
water is used. If you are experiencing problems with your non-air-jacketed bath, as an
alternative to buying a new bath, simply add a container of beads to your laboratory
oven or incubator. A container such as a stainless steel pan with 3-4" walls can be filled
with beads and placed into the heating unit. The container of beads will work great with
a minimal gradient. Such a container can be added to a standard incubation oven, a cell
culture incubator, or a refrigerator for cold incubations.
16. Can Lab Armor Beads be used for an ice bath without the Chill Bucket?
There are a number of different ways to use Beads. Many customers place containers
of Beads in their refrigerators, incubators and ovens.
When creating an ice bath, one goal is to keep the beads dry. So it’s a good idea to
separate the beads from the ice packs, which accumulate condensation. We
recommend using some kind of mesh wire or fabric. Also, any condensation that builds
on the surface of the beads will be able to drip through the mesh. It’s important to keep
the beads from soaking in water for extended periods of time. Besides attracting
contamination, excessive water contact will tarnish the surface of the beads and reduce
the fluidity of the bath. Also, as an alternative to ice packs, dry ice can be used to make
a colder bath (<0 ºC).

5. 17. Are the Beads safe?
The Beads do not contain any dangerous elements that will contaminate your
environment or pose health risks. The Beads are manufactured and batch analyzed by
metal optical emissions spectrometry. Lab Armor maintains strict quality controls on all
its raw materials and manufacturing outcomes. The Beads are designed to be used
safely at both low and high temperatures. For more information on safe working
temperatures of Lab Armor Beads, refer to FAQ #20 below or contact technical services
for specific recommendations.
18. How can samples be shaken or agitated in Bead Baths?
A shaker unit is still required for large bottles or flasks that need high rpm agitation,
such as 250 ml flasks for bacterial cultures. But for low speed agitation, a standard
laboratory rotator (such as a Lab-Line Maxi Rotator), a Bead tray, and a general-use
incubator, can replace a shaking water bath.
Here’s how it works:
Option 1) Samples are added to a StayTemp tray that is placed atop a rotator
inside a standard laboratory incubator and agitated at the desire temp.
Option 2) Warm Beads from a Bead Bath can be scooped into an insulated
WalkAbout tray and samples can be rotated on the bench top, outside the
incubator for 0.5 to 1 hr at temperature. We can provide larger insulated trays for
bottles and flasks too. In an incubator, the Beads actually transfer thermal energy
more efficiently to the samples than by air alone. And the Beads stay at
temperature ensuring consistent incubation despite folks opening and closing the
incubator door repeatedly.
19. Is the Lab Armor Bead Bath Available in 220v?
Yes. 220v units are available in 6L, 14L, and 20L Bead Bath sizes.
20. What is the working temperature of Lab Armor Beads?
For best performance use Lab Armor Beads at an operating temperature from -80 to
180ºC. However, product may be used up to 300ºC without loss in thermal
performance, but product fluidity may be reduced. Please contact technical services for
specific recommendations.
21. Can I try the 200 ml Test Drive in my water bath?
No, you will need to use a heat block. Add the sample to your dry bath by replacing one
Aluminum block. Allow the Beads to warm, monitor temperature, then add sample
vessels of various sizes and shapes. Try nonwater-tight vessels, such as petri dishes
and multiwell plates. Bury a microfuge tube containing a liquid such as water into the
Beads. Note that by eliminating exposure to surrounding air temperature, condensation
doesn’t accumulate under the lid.