Our FrameStar® two-component technology reduces evaporation from PCR plates, improving your results and allowing you to reduce the volume of expensive reagents to save you money.

FrameStar® plates combine the advantages of thin-walled polypropylene tubes for optimum PCR results, with a rigid polycarbonate frame to increase the thermal stability of the plate during the PCR process. This means that compared to a standard polypropylene plate, the FrameStar® plate will not warp and expand during rapid heating and cooling, meaning the integrity of seals will remain consistent and therefore less of your sample will evaporate.

This in turn means you can spend less money on expensive reagents, as you are retaining more during the PCR process.

To find out more about the benefits of our FrameStar® design, scroll down. Otherwise, please click on the button to browse our range. Each plate variety comes in a range of colours, including white wells for real-time PCR and qPCR.

Why our FrameStar® 2-component design is superior to standard polypropylene plates

FrameStar® PCR plates maximise thermal stability at high temperatures, which prevents sample loss by minimising thermal expansion during PCR. The two-component design combines the advantages of thin wall polypropylene tubes for optimum PCR results, and a rigid polycarbonate skirt and deck for the highest thermal stability and rigidity. In contrast to standard one-piece PCR plates, evaporation from the corner positions of the plate and outer rows of wells is minimal, which allows for the downscaling of reagent volumes and therefore saves costs.

  • Two-component technology reduces thermal expansion and sample evaporation.
  • Reduction of evaporation leads to improved consistency of PCR results.
  • Well spacing and position post-PCR remain accurate so liquid handling devices can reliably add or remove the smallest quantities from the plate.
  • Ideal for robotics, as plate distortion is eliminated post-PCR.
  • FrameStar® is ideal for assay miniaturisation due to rigid skirt eliminating warping, giving better sealing properties.
  • Cost saving due to downscaling of reaction volumes.
  • Lack of warpage reduces variation of fluorescent signals in optical assays, such as qPCR.

Thermal expansion of Polypropylene (PP) plates leads to evaporation from outer wells

PP is the optimum material for PCR tubes. It provides the most efficient heat transfer, as well as an inert surface with low binding capabilities for nucleic acids, proteins and other molecules. However, the material is not thermally stable in a plate format, and expands and contracts during each PCR cycle (Figure 1). Such thermal expansion will weaken the plate seal and leads to sample evaporation mainly from corner wells and outer rows.

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Figure 1: Standard plates with polypropylene frame expand by up to 2mm during thermal cycling, which leads to movement of wells away from the plate centre. This movement is most significant in the corner positions and outer rows of the plate. Sealing sheets do not expand at this rate so that the movement of wells will weaken the seal and lead to evaporation especially in corner positions and outer rows.

Thermal cycler blocks do not prevent thermal expansion of PCR plates

PCR blocks do not support PCR plates from the sides, and the high temperatures from the thermal block and heated lid accelerate expansion of the plates (Figure 2).

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Figure 2: Side-on view of a PCR plate in a thermal cycler. The sealed plate is sandwiched between the cycler block and the heated lid, but it is only partly fixed in position at the bottom of tubes, allowing the plate to expand horizontally.

FrameStar® 2-component technology reduces thermal expansion and sample evaporation

The polycarbonate frame of FrameStar® plates is significantly more heat resistant than standard PP plates, which reduces thermal expansion to a minimum. For this reason the seal integrity remains intact even at elevated temperatures during PCR. To illustrate this advantage of our two-component technology we have compared evaporation from one piece PP plates and FrameStar® PCR plates: Each well of a non-skirted 96 well plate (single piece, PP) and a Framestar® non-skirted design (code 4ti-0710) was filled with 10μl H2O. The plates were sealed with a qPCR adhesive (code 4ti-0560) and the weight of plates was measured before and after performing PCR (30 cycles x 15’’ 95°C; 15’’ 55°C). Table 1 shows that the average volume loss from one piece PP plates was 2.3μl per well which is equal to 23% of the total reaction volume. in contrast the volume loss from FrameStar plates was only 0.49μl per well using adhesive sealing.

For easier sample identification we now supply all microplate designs with a printed alphanumeric grid reference.

Plate Type
Starting Weight
Weight post PCR
Weight loss
Volume loss total/well

FrameStar® 4ti-0710

26.678g

26.631g

0.047g

47µl/0.49µl

One Piece

17.807g

17.586g

0.221g

221µl/2.3µl

Table 1: Weight and volume loss from 96well PCR plates. Results shown are averages from 5 plates of each plate type.One piece PP plates showed more than 4 times higher volume loss than FrameStar®plates.

Evaporation from one piece PP plates is highest in the outer wells

Since thermal expansion and movement of wells in one piece PP plates is enhanced around the edges of the plates (see Figure 1), evaporation is the highest from the two outer rows of wells. Figure 3 illustrates the levels of sample evaporation from different areas of PP plates. only the inner 32 wells of a one piece 96 well plate show low levels of evaporation, but sample loss is high from the two outer rows which contain more than 65% of the wells.

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Figure 3: Evaporation from the outer rows (red) is highest, medium level evaporation occurs in the second row (yellow) and sample loss from the inner 32 wells is lowest.

2-component plates improve consistency of PCR results FrameStar®

We have compared the degree of evaporation from different areas of one piece PP and FrameStar® PCR plates. First, the 64 outer wells (two outer rows) of both plate types were filled with 10μl H2O, plates were then sealed with a qPCR adhesive (code 4ti-0560) and their total weight determined before and after PCR. The experiment was repeated with a set of plates of which the inner 32 wells (green area in Figure 3) were filled. Table 2 shows that evaporation from outer wells of standard PP plates was significant and 65% higher than from inner wells. In contrast, FrameStar® plates showed low levels of sample loss across the plate.

The results show that reaction volumes remain consistent across the 96 wells (or 384 wells, data not shown) in FrameStar® plates. In contrast, the reaction volumes in standard plates will differ increasingly between wells during PCR. Buffer concentrations in outer rows will increase dramatically and result in reduced enzyme activity. In extreme cases samples will fully evaporate.

Plate Type

Starting weight (g)

Weight post PCR (g)

Weight loss (g)

Volume loss total/well (g)

FrameStar® 4ti-0710, outer 64 wells

26.230

26.193

0.037

37µl/0.57µl

One piece, outer 64 wells

17.299

17.118

0.181

181µl/2.8µl

FrameStar® 4ti-0710, inner 32 wells

25.841

25.824

0.017

17µl/0.53µl

One piece, inner 32 wells

17.132

17.078

0.054

54µl/1.69µl

Table 2: Weight and volume loss from different sections of 96 well PCR plates. Results shown are averages from plates of each plate type. Volume loss from the outer wells of one piece PP plates was 5-times higher than from FrameStar® plates.

FrameStar® 2-component technology allows for reduction of assay volumes and cost

Due to the much improved seal integrity, reaction volumes can often be reduced when using FrameStar® plates. Such downscaling of experiments can be successfully implemented without any loss of assay sensitivity or consistency (Figure 4) and reagent savings can be considerable.

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Figure 4: Comparable Ct values and mean deviations were obtained with 15μl and 25μl SyBr Green assays in heat sealed FrameStar® plates.

Plate Distortion Post-PCR

Distortion tests have been performed with different PCR profiles using a variety of sealing materials. The results shown were obtained using the following protocol with 5 μl reaction volumes, plates sealed with adhesive sheets (4titude® code 4ti-0500), in a Thermo Px2 Cycler: 1min 94ºC, 30x(30sec 94ºC, 30sec 55ºC, 30sec 72ºC), 5min 72ºC, holding step at 4ºC. Averages from measurements of 10 plate samples are shown. X- and Y- axis measurements were taken in the middle sections of the plate skirt. Warpage was measured as a maximum deviation from a flat plane. The results in Table 3 again demonstrate the high level of thermal stability of our FrameStar® plates compared to a standard one piece PP plate.

Plate Type

X-axis

Y-axis

Warpage

FrameStar® 96, skirted

0.02mm

0.02mm

0.03mm

One piece 96 well PP Plate

1.18mm

1.69mm

1.80mm

FrameStar® 384

0.02mm

0.02mm

0.03mm

One piece 384 well PP Plate

1.22mm

1.82mm

2.20mm

Table 3: Plate distortion post-PCR

Improved Sealing

In addition, FrameStar® technology provides a much improved level of seal integrity: During PCR, with heat seals or adhesive seals, the excessive thermal expansion/contraction of standard one-piece polypropylene plates can have a damaging effect on seal quality. This is especially evident around the edge of the plate where these forces are at their maximum resulting in significant sample evaporation from the outer wells. in contrast, the higher thermal stability of FrameStar® plates results in a reliable seal in all areas of the plate during PCR and in cold storage down to -80ºC.

Reduced Risk of Contamination

Raised rims around each tube aid the prevention of cross contamination between samples.

Plate Compatibility

FrameStar® plates are compatible with most PCR cyclers, real-time detection systems and sequencers. The plates have been successfully tested for reliable use on most automation platforms. Contact 4titude® for further details.


The FrameStar Range