VMS® Overview

A method for ensuring sample handling quality that complements Artel’s MVS and PCS, the VMS fills a potential gap in your process by measuring the sample volume present in each well – in-process – for virtually any plate or sample type. Using a unique, robust technology, the VMS seals each well and cycles through a series of repeated pressurizations to accurately and precisely determine sample volume in as little as 35 seconds for 96-well plates, and 110 seconds for 384-well plates.

Ideal for:

  • verifying sample volumes when you don’t have data on the accuracy and precision of the liquid handler used to generate the sample plate
  • determining sample volumes for solids, suspensions, or solutions
  • checking sample volumes in storage plates that may have experienced evaporation or water uptake

The VMS takes the guesswork out of sample and compound management.

 Artel Introduces the VMS®

Well Volume Verification

Get answers in seconds

1. Start with a sample plate
Calibrate the system for your specific plate type.

2. Measure the volume in every well
384-well plates are measured in less than 2 minutes.
96-well plates are measured in less than 35 seconds.

3. Analyze results and take informed action
Volumes are reported for every well and, based on specifications you set, problem wells are easily identified with color coding. Data can be exported for storage or further analysis.

System Capabilities

  • Customizable pass/fail specifications
  • Measures well volume in-process for greater accuracy at the time of assay
  • Increases efficiency by reducing wasted effort
  • Measures aqueous, non-aqueous, and DMSO-based solutions
  • Improves process control and data quality
  • Reduces cost and time for rework
  • Measures solids and suspensions
  • Integrates with plate handlers, stackers and LIMS
  • Reports well-by-well volume measurements
  • Compatible with virtually all 96- and 384-well plates of any shape, color, or type of plastic

Key Applications

The VMS supports a wide variety of applications through accurate and precise measurement of sample volumes:

  • In-process assay plate volume measurement
  • Determination of remaining volume in storage plates
  • Volume determination for accurate dilution and normalization


VMS® Accessories

Computer & monitor—controls VMS instrument, acquires and analyzes data

Shim Plates—optimize position on the plate carrier for certain plate types

Cleaning Plate—for weekly cleaning of the sealing gasket, use only with supplied disposable cleaning pads

Disposable Cleaning Pads—single-use pads to reduce cross contamination and optimal instrument performance

Metal Calibration Plate—assists with troubleshooting by simulating 0 µl to 352 µl, in 32 µl increments


VMS® Specifications

VMS Performance  
Volume Range 5-500 μL
Time Requirements 384 well plates < 110 seconds
96 well plates < 35 seconds
Weight 14 kg
COM port RS232

Volumetric Performance with Metal Test Plates*
Total Volume Random Error** Systematic Error***
< 150 µL < 2 µL ± 5 µL
> 150 µL < 2% ± 3%

*Volumetric performance in 96-well and 384-well plastic microplates can vary and must be determined for each plate type.

*Random error is expressed as standard deviation of n = 96 wells. This is sometimes referred to as imprecision or repeatability.

***Systematic error is expressed as the difference between the average measured volume and the nominal volume of the metal test plate. This is sometimes referred to as bias or inaccuracy.

VMS Computer  
Processor Intel Pentium CPU G3240T, 2.7 GHz
Memory  4 GB, DDR3 RAM
Hard disc 500 GB
Ports 5 USB
Networking options Gigabit ethernet
Peripherals Mouse, keyboard (US English)
Computer weight 2 kg
Monitor weight 4 kg
Operating System Microsoft Windows® 7&10 Professional Business (64-bit)

VMS Operating Conditions  
Temperature Operating: 18°C to 32°C (64.4°F to 89.6°F)
Storage: -29°C to 50°C (-20.2°F to 122.0°F)
Transport: -29°C to 50°C (-20.2°F to 122.0°F)
Humidity  Operating: 10 – 90% RH non-condensing
Storage: 10 – 95% RH non-condensing
Pollution degree 2
Installation class 2
Limit class Class A
(For industrial use. Domestic use restricted.)
Altitude Up to 2000m (6561ft) above mean sea level
Storage: As required for air travel
Dust No excessive dust



VMS® Frequently Asked Questions

What is the Artel VMS?

VMS stands for Volume Measurement System. It includes instrumentation and integration-ready software which provides in-process sample volume verification in most commonly used microplates. The system is suitable for liquid and solid volume measurements from 5 to 500 µL and reports the volumes in less than 2 minutes.

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How does the VMS work?

The VMS determines sample volumes by injecting each microplate well with a known volume of air and measuring the resultant pressure within the well. Using eight sensors – each one dedicated to a specific row – the resultant pressure is compared to a calibration curve and the volume of sample within the well is calculated.

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How is the VMS calibrated?

The VMS is calibrated by measuring the pressure in each of the empty wells of a chosen plate type, followed by measuring those same wells containing precision metal cylinders of known volume. A linear least squares fit is applied to the set of data points, producing a series of eight calibration curves – one for each sensor.

To determine sample volumes in every well of the plate, the measurements from each of the test wells are correlated to the calibration curve for the respective sensor.

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Can the VMS be used to measure any sample type?

Solutions (regardless of viscosity), solids and mixtures can be measured with the VMS.

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Can the VMS be used to measure samples in any plate type?

Most 96- and 384-well SBS plates less than 20mm high can be measured.

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What are the performance specifications of the VMS?

Volumetric Performance with Metal Test Plates*
Total Volume Random Error** Systematic Error***
< 150 µL < 2 µL ± 5 µL
> 150 µL < 2% ± 3%

*Volumetric performance in 96-well and 384-well plastic microplates can vary and must be determined for each plate type.

*Random error is expressed as standard deviation of n = 96 wells. This is sometimes referred to as imprecision or repeatability.

***Systematic error is expressed as the difference between the average measured volume and the nominal volume of the metal test plate. This is sometimes referred to as bias or inaccuracy.

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Does the VMS require regular maintenance?

Daily cleaning of the plate carrier and all exposed surfaces will reduce the amount of particulates or dust, which can cause erroneous readings. Monthly cleaning of the pressure bar, which forms the seal on the microplate, and periodic replacement of the pressure bar will be required depending on use. If the VMS is used regularly (daily or weekly), Artel recommends replacement of the pressure bar every 6 months (or more frequently if very heavily used).

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What are the advantages of the VMS over other volume measurement methods?

Sample volume measurement can be achieved using a variety of methods including gravimetric, absorbance, acoustic, optical and fluorescence. Uniquely, the pressure-based technology of the VMS:

  • Measures any liquid or solid sample including DMSO, viscous solutions and liquid/solid mixtures such as tissue samples in extraction solution.
  • Measures volumes in most microplate types.
  • Is not subject to issues such as scatter of signal without reaching the detector, the requirement of a complete and flat sample meniscus, and dependence on sample color and material.
  • Provides in-process volume measurement.

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How do does the VMS deal with cross-contamination?

If sample solutions are contained inside the microtiter wells, then contamination should not be an issue. If sample droplets are located on or near the lip of the well, then a best practice to follow is to spin down the samples in the plate using a centrifuge, if possible.

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Can the VMS be integrated with existing software/LIMS?

Yes. A Software Development Kit is provided as part of the system installation, including example applications, source code, and documentation of the API.

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What is the tallest/shortest plate the system can read?

A plate must be less than 20mm to fit inside the VMS. If it is a short plate, it can usually be shimmed for reading. The ideal height is a plate approximately 16mm tall.

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Can the VMS read tube racks?

The VMS can read tube racks that are lower than 20mm and have tubes that are locked into the rack (i.e. REMP STBRs).

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Can the VMS read barcodes?

There is not a built in barcode reader within the VMS. However, the system software does support an external reader and one may be purchased with the system.

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How fast can the VMS read a plate (96/384)?

The volumes contained in 96-well plates can be read in 35 seconds and sample volumes in 384-well plates can be measured in 110 seconds.

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What results are given by the VMS and are they configurable?

The volume measurements are displayed in the user interface after a plate is measured and can have multiple visual pass/fail parameters applied. The data are also saved in a pdf report and .csv file in a user-selected location.

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What will happen to the VMS results if there are bubbles in the sample?

Because the air inside the bubble is compressed the same as the air around the sample, bubbles do not affect the measurement in most cases.

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What if the liquid is stuck to the side of the well?

Because the VMS is reading pressure in the volume of air surrounding the sample (whether the sample is liquid or solid) it does not matter if the liquid is on the side of the well.

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How can the VMS improve quality and productivity in the lab?

Some of the more common uses for the VMS are:

  • Real time process verification
  • Assay process optimization
  • Automated liquid handler performance verification
  • Liquid class optimization during design of novel instrumentation
  • QC of reagent addition during PCR
  • QC of incoming collections of materials

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How can I learn more about the VMS?

Fill out this form to request additional information or contact Artel at 888-406-3463 and speak with one of our Sales Representatives.

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Why is sample volume measurement important?

Assuring the quality of the sample volume measurements made in the lab is the first step toward achieving superior assay data.

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VMS® Software

Using a menu- and icon-driven interface, the VMS Data Manager software walks the user through both plate calibration and measurement operations. Measurement data is immediately available visually, with out-of-specification wells indicated by color, and quantitatively. Data is exported in a CSV file for further analysis.

Software features

  • Ability to determine volumes of any solid or liquid sample
  • Flexible definition of sample locations
  • Ability to define any microplate type as the measurement vessel
  • Flagging of all wells exceeding tolerance limits
  • Compatible with Windows 7
  • Easy exporting of data for analysis.