Thermo-Shaker Buying Guide: How to Choose a Thermomixer for Your Lab

Think about making hot cocoa. Warm milk on its own leaves the powder sitting at the bottom, and stirring cold milk takes forever. Warmth and motion together are what get it mixed. A thermo-shaker does the same job for your samples: it holds tubes or a plate at a set temperature while shaking them in a small, fast circle.

You will also see it sold as a thermomixer, thermal mixer or heated tube shaker. It is a compact benchtop unit with a metal block shaped to fit your tubes. The block heats (and on some models cools), and the whole platform moves in a tight circle. The diameter of that circle is called the shaking orbit. On tube thermo-shakers it is tiny, just 2–3 mm, which lets the unit run at high speeds that keep small volumes moving.

So how do you choose one? Start with the temperatures your protocols need and whether any of them sit below room temperature, then check speed and orbit, the block formats for your labware, temperature accuracy, and whether a heated lid and programming matter for your runs. This guide walks through each in plain terms and ends with a side-by-side comparison of three Novara™ models.

What a thermo-shaker does (and what it doesn't)

Many tube protocols need two things at once: a steady temperature so a reaction or digestion runs at the right rate, and gentle, constant agitation so the sample stays evenly mixed. Cell lysis, enzyme digests, bacterial outgrowth and resuspension steps are common examples. A thermo-shaker handles both in one footprint, so you are not juggling a heat block and a vortex mixer.

It helps to know how it differs from equipment that looks similar:

• Dry bath or heat block: heats tubes but does not mix them. Fine for static incubations; for mixing you have to stop and vortex by hand.
• Vortex mixer: mixes fast at room temperature. Great for short mixing steps, not for timed incubations. See our multi-tube vortex mixer guide.
• Heated microplate shaker: built for several microplates at once, with a heated lid over the plates. See our heated microplate shaker guide.
• Incubator shaker for flasks: a large cabinet with a wide orbit for culture flasks. Its speed ceiling is too low for small tube volumes.

The temperatures you'll actually use

Most everyday tube work sits in a fairly narrow band. Enzyme digests usually incubate at 37°C, a classic heat shock for transforming competent cells runs at 42°C for 30–60 seconds, cells then recover at 37°C with shaking, and a common way to stop a restriction enzyme is 70°C for 15 minutes.^[2][3] Genomic DNA lysis with proteinase K runs at 56°C.^[4]

Those three numbers come up so often that one university lab's operating procedure for its thermomixer lists pre-set buttons for exactly 37°C, 42°C and 56°C.^[5]

Why do thermo-shakers go all the way to 100°C, then? Some steps denature DNA or proteins, and heat-stable enzymes make high-temperature work possible. The enzyme behind PCR, Taq polymerase, comes from Thermus aquaticus, a bacterium discovered after microbiologist Tom Brock began research trips to Yellowstone in 1966. It made its entire living in the scalding waters of Mushroom Spring, and its enzyme is useful because it is stable at the high temperatures PCR requires to denature DNA.^[1]

Heating only, or heating and cooling?

This is the decision buyers most often get wrong. A heating-only thermo-shaker can only add heat, so the lowest temperature it can hold is a few degrees above the room it sits in. On the Novara Thermo-Shaker, the heating-only TS-H controls from room temperature +5°C up to 100°C. The TS-HC adds active cooling and controls from room temperature −30°C up to 100°C.

In practice, choose active cooling if you need any of these:

• Cold holds: holding samples at 4°C or below room temperature, for example before or after an overnight run.
• Precise room-temperature steps: steps that must stay at or just below room temperature in a warm lab, where a heating-only unit simply cannot get there.
• Fast cool-down: the TS-HC brings its block from 100°C back to 25°C in ≤10 minutes, so a hot step can be followed by a cooler one without waiting.

If everything you run is at 37°C or warmer, heating-only is simpler and costs less.

Five more things to check before you buy

1. Speed, orbit and mixing

Small tubes need a small, fast orbit to set their contents in motion. The Novara models use a 3 mm orbit (TS-H and TS-HC) or a 2 mm orbit (Duo TS-H2), with top speeds of 1,500 to 2,000 RPM. Agitation is not a nice-to-have in every protocol, either.

Look for fine speed control so you can match a written protocol, and a range low enough for gentle resuspension.

2. Block formats and capacity

Match the block to your labware before anything else. The Novara Thermo-Shaker takes one interchangeable block at a time, and bigger tubes come with lower speed limits:

• Microtubes: 54 × 0.5 mL, 35 × 1.5 mL or 35 × 2.0 mL tubes, or a combo block for 15 × 0.5 mL plus 20 × 1.5 mL.
• Plates: 96 × 0.2 mL PCR plate or strips, or a 96-well ELISA or deep-well plate.
• 5 mL and 10 mL tubes: 24 × 5 mL or 15 × 10 mL tubes, rated to 1,000 RPM.
• 15 mL and 50 mL tubes: 12 × 15 mL conical, 6 × 50 mL conical or 6 × 50 mL round-bottom tubes, rated to 800 RPM.

The Novara Duo holds two independent blocks for PCR plates and 0.5 mL, 1.5 mL or 2.0 mL tubes, so you can run two sample sets, temperatures or protocols side by side.

3. Accuracy, uniformity and heat-up time

Check accuracy and uniformity across the whole block, not just at the sensor. The TS-H and TS-HC are rated at ≤±0.3°C for both, and the Duo at ≤±0.2°C at 37°C. Heat-up time tells you how long you wait before you can start: 25°C to 100°C in ≤12 minutes on the TS-H and TS-HC, and in ≤15 minutes on the Duo.

4. A heated lid

During long or hot incubations, vapor rises out of the sample and condenses on the cooler underside of the tube cap, which changes your volume and concentration. A heated lid keeps the top of the tubes warm too. The Duo has a heated lid, switchable between automatic and manual, that clamps over both blocks to prevent condensation and evaporation and reduce the risk of tube bursts at high temperatures.

5. Programming, safety and footprint

Multi-step programs let one run go from, say, digestion to heat inactivation without you standing by. All three Novara models store up to 5 steps with up to 99 cycle repeats, resume automatically after a power interruption, and include over-temperature protection. Finally, check bench space: the single-block units measure 10.2" × 7.7" × 5.9", and the Duo 13.4" × 12.6" × 7.9".

Three models side by side

Here is how the heating-only TS-H, the heating-and-cooling TS-HC and the dual-block Duo TS-H2 compare. All three use PID temperature control, a brushless DC motor and an LCD showing live and set values.

Feature	TS-H	TS-HC	TS-H2 (Duo)
Blocks	1 interchangeable	1 interchangeable	2 independent
Temperature control range	RT+5°C to 100°C	RT−30°C to 100°C	RT+5°C to 100°C
Active cooling	No	Yes	No
Speed range	200–1,800 RPM	200–1,500 RPM	200–2,000 RPM
Orbit	3 mm	3 mm	2 mm
Temperature accuracy	≤±0.3°C	≤±0.3°C	≤±0.2°C at 37°C
Heat-up time	25°C to 100°C in ≤12 min	25°C to 100°C in ≤12 min	25°C to 100°C in ≤15 min
Block formats	0.5 mL to 50 mL tubes, PCR and ELISA/deep-well plates	0.5 mL to 50 mL tubes, PCR and ELISA/deep-well plates	0.5 mL, 1.5 mL and 2.0 mL tubes, PCR plates
Heated lid	Not listed	Not listed	Yes, automatic or manual
Programming	Up to 5 steps, 99 cycles	Up to 5 steps, 99 cycles	Up to 5 steps, 99 cycles
Dimensions (L × W × H)	10.2" × 7.7" × 5.9"	10.2" × 7.7" × 5.9"	13.4" × 12.6" × 7.9"
Weight	16.5 lbs	18.7 lbs	23.6 lbs
Best fit	Warm incubations and lysis in one tube format at a time	Protocols that need cold holds or fast cool-down	Two protocols or temperatures side by side

In short: the TS-H covers most warm incubations and lysis work, the TS-HC is the one to pick if anything in your workflow sits at or below room temperature, and the Duo doubles throughput when two protocols compete for the same instrument.

Novara TS-H

1 block · RT+5°C to 100°C · 200–1,800 RPM

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Novara TS-HC

1 block · RT−30°C to 100°C · 200–1,500 RPM

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Novara Duo TS-H2

2 blocks · RT+5°C to 100°C · 200–2,000 RPM

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Tips for consistent results

1. Pre-warm before you load. A heat shock lasts only 30–60 seconds,^[2] so the block must already be at temperature when the tubes go in.
2. Balance the block. If your program includes shaking, place tubes symmetrically so the block stays balanced.^[6]
3. Verify with a thermometer. Do not check a block's temperature by touch; use a thermometer.^[6] A calibrated probe is also the simplest routine QC check.
4. Use heat-resistant labware. Make sure your tubes and plates are rated for the temperature you are running.^[6]
5. Respect block speed limits. Run larger tubes within their block's speed limit, and increase speed gradually until the liquid moves without reaching the cap.
6. Let it cool before changing blocks. The platform and lid heating surfaces stay hot after a run, so give them time before swapping blocks.^[6]

Which setup fits your lab?

• Your protocols run at 37°C or warmer (digests, outgrowth, lysis, heat inactivation): a heating-only thermo-shaker such as the TS-H is usually enough.
• You need 4°C holds, room-temperature steps in a warm lab, or fast cool-down: choose active cooling, like the TS-HC.
• Two people or two protocols compete for one unit: the Duo TS-H2 runs two blocks independently.
• You mostly incubate several microplates at once: a heated microplate shaker is a better fit.
• You only need fast mixing, no heat: a multi-tube vortex mixer costs less and takes less space.

Frequently asked questions

Is a thermo-shaker the same as a thermomixer?

Yes. Thermo-shaker, thermomixer, thermal mixer and heated tube shaker all describe the same type of benchtop instrument: a temperature-controlled block that also shakes. Names vary by supplier.

Can a thermo-shaker cool samples?

Only if it has active cooling. Heating-only units like the TS-H and Duo TS-H2 control from 5°C above room temperature upward. The TS-HC can cool to 30°C below room temperature.

What speed should I use for 1.5 mL tubes?

Follow your protocol or kit instructions first, since that speed was validated with the assay. If none is given, start moderate and increase until the liquid is clearly moving without reaching the cap.

Can I use 15 mL or 50 mL tubes in a thermo-shaker?

Yes, with the right block. The Novara Thermo-Shaker has blocks for 12 × 15 mL conical tubes and 6 × 50 mL conical or round-bottom tubes, rated to 800 RPM because of the larger volumes.

Do I need a heated lid?

For short incubations at moderate temperatures, usually not. For long or near-boiling steps, a heated lid reduces condensation under the caps and keeps sample volumes consistent.

Still deciding? Browse the full range of Novara temperature control equipment, or contact our team with your tube formats and protocol temperatures and we'll help you choose.