Anachem Pipette Service FAQs

Anachem Certification

A. Based on rigorous documentation, extensive training, and long-term proficiency testing, Anachem’s Pipette Service division has achieved the highest level of calibration competency and data integrity when using the gravimetric method. It has held UKAS accreditation since 1998 and now provides a single point for servicing of all major brands of pipettes to this level.

When you choose UKAS calibration you will receive additional information on your Calibration Certificate including statement of measurement uncertainty per volume setting. Whether or not you choose this option, Anachem’s Pipette Service complies with all quality standards as set forth by ISO guidelines and UKAS interpretation, assuring you of the highest level of calibration competency and traceability.

Isn’t it comforting to know that UKAS auditors have ensured the highest calibration standards are being met, so you can trust your service provider.

A. ISO/EN8655 is an international standard for the volumetric calibration of Piston Operated Volumetric Apparatus (POVA). The standard, which is in seven parts has become an ISO standard and a European Norm and all European National Standards such as BS6018, BS7532 and DIN 12 650 have been superseded in its favour.

Calibration methods are detailed in the standard and the gravimetric test is the reference method. Maximum errors for trueness (Inaccuracy) and precision (CV%) are listed for all types of POVA device.

The standard states "Apparatus shall be calibrated with noted tips. (A pipette calibrated with a specific tip shall only be deemed within calibration with that tip)".

ISO:8655 recognises pipettes, tips and service as a complete system.

CYCLERtest FAQs

A. Yes. CYCLERtest is a completely independent validation system and as long as your thermal cycler has a regular 0.2ml, 0.5ml or 384 well block Anachem can carry out the validation. We can also test gradient cyclers with our special gradient protocol, and multiple and/or exchangeable blocks.

A. Yes, there is a new wireless version of CYCLERtest which has been specifically designed to measure the closed (q)PCR/RT-PCR system. It works by sending the results to the hardware box via radio waves. This system is compatiable with the ABI 7500, ABI 7300, ABI 7900HT with standard 96 well format and Stratagene MX3000 and MX3005P systems. Roche light cyclers can also be validated.

A. Yes, when the denaturation temperature is too high, the DNA polymerase will soon loose activity during the PCR process, resulting in low or no yields. Annealing temperatures are very specifically determind. Changes will result in specific bands or no annealing at all.

A. By registering on the Driftcon web site www.driftcon.com you can obtain up to 5 different protocols free of charge.

A. The CYCLERtest validation can be carried out with either the headted lid being open or closed. The heated lid does not have an effect on the performance of the heating and cooling system under the well, which is what the system is designed to measure. However with the introduction of the wireless system the compete validation can be performed with the heated lid closed.

A. We advise to have a validation test at least every year, or every 250 runs, whatever comes first. Some laboratory, national or international regulations might require you to do this more often. We would therefore suggest you take advice from your accredited authority.

A. It will be very difficult. CYCLERtest uses the MTAS (Mobile Temperarure Acquisition System) that was developed by GENOtronics. It uses very sophisticated temperature sensors (thermistors), electronics and software algorithms, to correct for possible deviations. The overall accuracy of this system is better than 0.1ºC. It also makes dynamic multichannel measurements.

A. We test your thermal cycler against internationally accepted standards, and the measurement system itself is complying with the offical temperature measurements regulations. This means that if you have your thermal cycler performance tested with our system, it is also validated according to these regulations.

A. You can purchase these from Anachem. The specifications will be loaded onto your computer when you synchronise with CYCLERtest via the Driftcon software.

Please call 01582 747500 or e-mail pipetteservice@anachem.co.uk for pricing information.

A. We have also developed the Driftcon system for checking the performance of your cycler on a monthly, weekly or daily basis. It is an end user temperature measurement fixture that will show the drift of the accuracy and the spread of your thermal cycler in time, and in relation with the global field specifications of that brand and type of cycler.

A. If your machine fails, the generated report will allow you to make an informed decision based upon the errors found. If the errors are small you may decide they are acceptable. If the errors are found in a specific area then this would suggest a mechanical fault and therefore repairs would be needed. You would then need to return your thermal cycler to the manufacturer.

A. Due to the lack of control, cyclers often are not able to reach a target temperature in a stable way. This means that a denaturation temperature can go much higher that the set temperature, before reaching a plateau. For the annealing temperature plateau, undershoots of up to several degrees are not uncommon.

A. Accuracy is defined as the difference in display and the actual block temperature. Spread (or non-uniformity) is the difference in the temperature between the wells of a cycler block.

A. The CYCLERtest (MTAS) validation is a far more detailed and dynamic validation check compared to that carried out when your machine is serviced by the manufacturer.

Anachem by using CYCLERtest will provide you with a comprehensive report on how your machine is performing. We will not service the machine and repair problems which are found during the test.

A. The test report is encrypted and so can not be modified by an external source. A certificate of Thermal Validation accompanies every test report, this certificate represents the results of the measured and calculated parameters of the tested instrument.

A. There is no ’warranty’ on the test. We show the output performance of your cycler at the time of measurement. The performance measurement cannot predict what will happen with the accuracy and spread of your cycler in time, nor will it predict if your cycler breaks down the next day. Thermal cyclers wear in time and so will their performance.

A. Despite all the data that has been collated, CYCLERtest and Anachem will refrain from making any statements on this issue. First of all, we want to be completely independent. Secondly, it is very difficult to make general statements about certain brands or types, because there are already hugh differences between machines of the same type or brand, and also the age of the cycler is of influence.

A. The positioning of the probes has been devised by using empirical and mathematical data in order to place the probes in the optimum positions for accurate and precise temperature measurements.

A. Each well is not individually controlled by the heating and cooling system threfore the positions selected allow an overview of the block to be ascertained, however if you specifically require all wells to be tested this can be carried out. Please contact Anachem to discuss this further.

A. It is very important to know how your thermal cycler behaves. Negative results could be caused by temperature differences in the block, and could be positive in reality. Biological controls are not sufficient to compensate for these differences as variances can occur between wells.

Pipette Service & Maintenance

A. Anachem guarantees that parts are replaced with new, high quality spares. This commitment to quality allows us to warranty our service for 12 months.

A. The frequency of both service and re-calibration is based on risk assesment. The risk assesment is likely to consider the frequency of the use of the pipette, the corrosiveness of the liquid being pipetted and the risk to the business if the pipette goes out of calibration. This would normally result in the decisions on how often being set between 3 months and a year.

A. As a population, pipettes checked annually without any preventative maintenance or regular servicing procedures in place, will have a 20% or more failure rate.

Over 60% of pipette failure is attributable to sealing system defects. This is predictable but preventable. Under normal use and based on manufacturer’s recommendations seals should be replaced at least once per year, while tip holders and pistons should be replaced every three to five years. Seals, o-rings, tip holders, tip ejectors and the volume adjustment knobs can easily be changed in your own laboratory without affecting the calibration of your pipettes There are however a number of parts that when changed can alter the pipettes calibration. These parts include the piston and piston assembly, friction o-ring, operating rod and volumeter. When these need changing it is best to return your pipettes to your service provider for replacement and pipette re-calibration.

A. Prevention is better than cure. It is recommended that you check your pipettes daily before use and establish a routine for basic servicing. There are a number of basic care checks for your pipettes that can be performed in your own laboratory to maintain correct functionality in between full servicing. These include a simple functionality check and a visual leak test.

Pipette Service Technical Points

A. The Gravimetric test is the most commonly used method for pipette calibration by pipette manufacturers and international standard organisations.

It is based on the determination of the weight of water samples delivered by the pipette. Implementation of this method requires the strict monitoring of environmental conditions and the systematic use of adequate and controlled equipment. Ambient temperature, barometric pressure and relative humidity must all be checked and regulated.

Conversion of weight to volume must take into account the density of the liquid as well as evaporation during the cycle time. For each measurement, the corresponding volume (Vi) can be calculated as follows: Vi = (Wi + e) Z.

Wi is the weight as read on the balance, e is the mean evaporation loss during the cycle time, Z expressed in µl/mg, is a conversion factor incorporating density of water buoyed in air, at test temperature and barometric pressure.

Always calibrate to ISO standards.

A. Anachem always replace seals & O-rings during service maintain high levels of accuracy & precision.

Other service agancies who wish to reduce costs, may use grease to obtain an air-tight seal rather than replacing parts. Many commonlu used pipettes are not designed as a greased system and this quick fix will have long term detrimental effects on pistons and tip holders with a loss of calibration over time.

A. For mechanical reasons, pipettes can only deliver samples accurately over a limited range of volumes for each particular model.

Ideally, the volume of liquid delivered in that range follows a precise linear relationship to that selected. It is essential to check this linearity when the pipette is serviced to ensure correct functionality at both the upper and lower limits of the pipettes capacity.

Even with Anachem’s most basic level of service, volumes are checked at both extremes of a pipettes range. Our standard service level is 2.2, meaning two volumes are checked with two weighings to ensure both accuracy and linearity.

To increase their throughput some other service agents only perform checks at a single mid-point volume with three or five weighings, and even issue calibration certificates based on these minimal readings.

As the majority of pipettes are variable volume how can you ensure that a pipette is linear across it’s specification range by testing only one volume?

Always ask what level of service you are getting for your money.

A. If you apply grease to the internal parts of a pipette, it will need to be removed with a solvent for cleaning during servicing. The amount of grease re-applied may vary and could alter the calibration of the pipette.

Dry-seal pipettes maintained in the correct way, should never require grease to be applied. They can be cleaned and seals and O-rings replaced without altering the calibration.

Anachem always replaces these critical dry-seal parts during servicing to maintain high levels of accuracy and precision. Other service agencies who do not use quality spare parts or who wish to reduce costs, rather than replacing parts, may use grease to obtain an air-tight seal. Grease may harbour contaminants within the pipette, introduced through aerosols or when pipetting volatile liquids. These are retained in the grease and may advance corrosion of internal pipette parts such as pistons.

Such damage may increase costs as additional parts are required more frequently than if the pipette is correctly maintained. For pipettes that are not designed as a greased system this quick fix will have a long term detrimental effect on the pipette with a loss of calibration over time.