PIPETTES

  1. How should I work with my HTL pipette?
  2. What is pipette maintenance?
  3. What is pipette calibration?
  4. Why do I need to have my pipettes calibrated and maintained?
  5. How often do I have to calibrate my pipette?
  6. What does inaccuracy and imprecision mean?
  7. What is ISO 8655?
  8. Can I calibrate my HTL pipette myself?
  9. How can I sterilize my pipette?
  10. Are HTL pipettes UV resistant?
  11. What is the warranty for HTL pipettes?
  12. What do I do if my pipette works improperly?
  13. Is my pipette resistant to chemicals such as….
  14. How should I aspirate viscous and dense liquids?
  15. How should I set the volume of a variable volume pipette?
  16. Are the HTL pipettes ergonomic?
  17. What parameters affect the accuracy of my pipette?
  18. Is my HTL pipette durable?

PIPETTE TIPS

  1. How to disassemble and assemble the ejector and also how to adjust the length of the pipette ejector?
  2. Can I use other manufacturers’ tips with HTL pipettes?
  3. How often do I need to change a tip?

PIPETTE CONTROLLER & SEROLOGICAL PIPETTES

  1. How can I sterilize my Swiftpet Pro?
  2. Can I replace the battery of Swiftpet Pro?
  3. How long does it take to recharge the battery?
  4. What is the warranty for HTL pipette controller?
  5. Can the serological pipettes be sterilized in an autoclave?
  6. Why do the serological pipettes have a negative graduation which goes beyond the volume indicated?

REPETITIVE DISPENSER Minilab 201 & SYRINGES

  1. Can I sterilize the syringes in the autoclave?
  2. Can the adapter for 25 & 50 ml syringes be autoclaved?
  3. Is sterile version of the syringes available?

Answers:

PIPETTES

1. It is important to handle your pipettes properly to maximize their longevity and maintain accurate readings.

It is recommended to:

  • Always store your pipettes upright. Leaving them flat on the bench, especially with liquid in the tip, could cause the liquid to enter the shaft and piston area of the pipette and result in corrosion.
  • When using a pipette, push the plunger down to the first stop and hold, then insert the tip into the liquid at a vertical or 20 degree angle. Slowly release the plunger so the liquid goes into the tip without a sign of bubbles.
  • Always abide by the volume usage specified by the manufacturer. For example, do not try to use a 100-1000µl pipette to draw up 50µl of liquid.
  • Calibrate your pipettes at least on an annual basis to ensure that they are in specifications and cleaned thoroughly.
  • Clean the pipette regularly.

2. Pipettes require regular cleaning, lubrication and calibration to maintain their performance over time.

3. It is a test of your pipette performance – to check whether the measurement results are within the permissible errors specified by the pipette manufacturer on the basis of ISO 8655 standard. A calibration certificate listing the instrument’s accuracy and precision is issued for each pipette manufactured at HTL.

4. Pipette performance can change over time due to leakage, wear on parts and contamination. Cleaning and maintenance help eliminate these sources of incorrect dispensing. However, the accuracy and precision of your pipettes must be checked at regular intervals. Many quality systems and standards, such as GLP or GMP requirements and the ISO 9000 series, require that a regular, documented maintenance and calibration procedure be in place for all instruments. Regular pipette calibration helps increase the quality and reliability of all procedures in which they are used.

5. According to International Standard ISO 8655, pipettes need to be calibrated regularly, at least once a year or even more often, for example, every three to six months. The interval should be determined by the frequency of use, the types of liquids handled and the quality requirements of your particular application.

6. Inaccuracy (A)  is the difference between the volume dispensed and the test volume selected. Imprecision (P) is the degree to which repeated measurements under unchanged conditions show the same results.

7. International Standard ISO 8655 specifies the requirements for pipettes and pipette calibration laboratories, providing detailed guidance for the respective environmental conditions, procedures and equipment. Pipette calibration in accordance with ISO 8655 is performed using a repeatable and reliable measurement technology and equipment, such as balances, in a carefully controlled environment.

8. Every HTL pipette is delivered with a calibration tool to enable pipette recalibration by the user. Detailed information on calibration procedures can be found in pipette instruction manual.

9. Autoclaving
Autoclaving is the simplest sterilization method if all pipette parts tolerate extreme heat. To achieve sterility, a holding time of 20 minutes at 121°C (252°F) is required.

  • Fully autoclavable HTL pipette models: DISCOVERY PRO, DISCOVERY COMFORT, LABMATE PRO, CLINIPET+
  • Autoclavable lower parts: OPTIPETTE (see instruction manuals for details).

Chemical disinfection and sterilization
Chemical disinfectants are used to decontaminate surfaces and equipment if autoclaving is not possible or practical.
The choice of a chemical disinfectant depends on the microorganisms of concern. Also, the chemical compatibility of the materials should be taken into account (see instruction manuals for details). If the shaft and the tip ejector of a pipette have to be chemically decontaminated, the pipette should be disassembled according to the instruction manuals.

10. HTL digital pipettes are UV resistant, which was confirmed by our tests. The recommended distance from the radiation source to exposed element should be not less than 50 cm. Prolonged and very intense UV exposure can cause de-coloration of pipette parts, without affecting pipette performance.

11. For warranty information please contact your local HTL distributor.

12. Step 1
Whenever you notice improper functioning of HTL equipment, take a look at the information available at this website and in instruction manual of your product. It might occur that the reason of the malfunctioning is prosaic and that simple action can fix your tool.
Step 2
Should the problem noticed occurred to be more severe, please contact to your local distributor and if he asked you to return the product, please decontaminate it and send it back to him/service together with filled Claim Form.
Notice! Filling the Claim Form is necessary condition for claim examination because of safety considerations.

13. HTL pipettes are manufactured with use of highly durable materials. While working, please consider chemical resistance of the following plastics: PEI, PP, PC, POM, PA, PPS, PVDF used to produce the pipette parts.

14. Method 1. Pre-rinsing technique. Pre-rinsing is a technique recommended when working with viscous and/or dense liquids. Some liquids show a tendency to cling to the inside and outside surfaces of the disposable tips (especially serum, protein-containing solutions, and organic solvents), resulting in an error that may be larger than the tolerance specified. To insure that this surface tension does not cause variations in the volumes you aspirate, always pre-wet the disposable tip with the sample before use. Aspirate some liquid and then dispense it back into the original container. Successive samples from this same tip will exhibit good reproducibility (low variance). Pre-wetting is recommended in most preparations for improved accuracy
Method 2. Reverse pipetting technique. The reverse pipetting is another technique especially recommended for pipetting solutions with a high viscosity or those that tend to foam. This method is also recommended for dispensing very small volumes. The advantage of this mode is reducing error due to film retention. The sequence of operations in the pipetting process is reversed, as follows:
1.Press the operating button to the second stop
2.Dip the tip into the liquid, and then slowly release the operating button. This will fill the tip with a volume that is larger than the set volume. Wait 1-2 seconds to reach equilibrium in the tip and withdraw the tip from the solution, touching it against the edge of the reservoir to remove excess liquid.
3.Dispense the liquid into the receiving vessel by pressing the operating button gently and steadily to the first stop. This volume is equal to the set volume. Hold the button in this position. Some liquid will remain in the tip, and this should not be dispensed.
4.Remove the tip from the receiving vessel without blowing it out. The liquid remaining in the tip can be delivered into the original vessel or discarded together with the tip.
5.Release the operating button to the ready position.
Reverse pipetting is only possible with air displacement pipettes.
Method 3. Compensation for solutions of density much different from water is possible by setting the digital micrometer slightly higher or lower than the required volume. The amount of compensation must be determined empirically.

15. The volume display shown by the counter has three digits, which should be read from top to bottom. In addition the lowest counter drum is printed in a scale which enables the setting of the volume in the minimum graduation range.
To set the required volume, use:
1. the lower section of the pipetting pushbutton (single- and multichannel DISCOVERY Comfort and LABMATE pro pipette series)
2. black adjustment knob (single- and multichannel DISCOVERY Comfort and LABMATE pro pipette series). DISCOVERY Comfort are equipped additionally with the locking system.
All volume setting procedures should end in the reduction of volume setting from a position just above the desired level to that level. As further examples:
When moving from a high volume setting to a lower value, the pushbutton or adjustment knob should be rotated at normal speed, clockwise, to take the setting just above the desired level. It should then be further rotated very slowly till the desired volume is shown on the digital volume display. In the event that you overshoot the desired setting, repeat the procedure by increasing the volume to a position just above the desired volume and then once again, reduce slowly to the desired level.
When moving from a low volume setting to a higher value, the pushbutton or adjustment knob should be rotated at normal speed, anticlockwise, to take the setting to a position just above the desired level. Then reduce the reverse the rotation and slowly adjust back until the desired volume is shown on the digital display. Once again, in the event that you overshoot the desired setting, repeat the procedure by increasing the volume to a position just above the desired volume and then reduce slowly to the desired level.

16. The design of HTL pipettes bases on decades of experience and reflects our deep understanding of end users needs and preferences. Within the years HTL representatives have paid hundreds of visits to all kinds of laboratories, on every continent in search for the most optimal characteristics of the manual liquid handling tools. This never ending research work of our dedicated distributors and our marketing crew allows us to find an ideal equilibrium between pipette weight, materials applied, forces necessary for smooth but precise pipetting as well as the pipette handle shape. Extensive pipetting is a hard physical work which in some extreme cases may cause Repetitive Strain Injuries (RSI). While crafting our pipettes we made sure that their properties give the user the sensation of comfortable work with the most popular pipettes on the market, but at the same time they minimize strain and potential risk of RSI.
The most important pro ergonomic features of HTL pipetting systems are:

  • Low pipetting forces
  • Carefully designed handles
  • Low tip ejection forces
  • Convenient volume setting system
  • Smooth Pipetting

The pipetting forces of all HTL pipettes belong to the lowest in the industry. Our research work of the last 3 years was aimed in particular at pipetting force reduction. The newest models of our pipettes feature low tension springs as well as smoothly running plunger sealing system resulting in effortless pushbutton operation at both pipetting and blowout stages.
HTL pipettes are renowned for their convenience and the sensation of the “familiar feel”. While the pipette feels in the hand as the most popular pipettes on the market it offers wide finger support allowing for convenient hanging of the pipette on the index finger and relaxed grip. The weight of the HTL pipette gives the laboratory professional an optimal balance between low strain and secure pipette handling. The newest DISCOVERY PRO pipettes offer slim pipette handle, fitting even for the smallest palms as well as new pipette and ejector pushbuttons. The diameters of the pushbuttons, together with their smoothly shaped edges ensure comfortable handling.
The hollowed finger rest of the DISCOVERY PRO, together with their slim handle were designed to get rid of spare grams of plastic which can mean so much after hours of intense pipetting.
The fixed volume CLINIPET+ pipettes were designed exclusively as the fixed volume Pipettes. Their handles carry only the components necessary for accurate work of the fixed volume pipette, thus they are slimmer and lighter than most fixed volume pipettes of other manufacturers. The CLINIPET+ pipettes are equipped with a unique tip ejector button. The ejection is performed by sliding the button to the left or right. This effortless movement offers relief to the tendons of the thumb worn out during ejection of the tips with other standard pipettes.
HTL pipettes are equipped with a number of systems aimed at reducing the force of tip ejection. The revolutionary system applied by HTL for reduction of the tip sealing and ejection force bases on the concept of retrievable shafts and cones. During the sealing of the tip on the pipette the pipette is being pressed against the rack of the tips. When the pressing force applied to the pipette is sufficient for secure sealing the shaft starts to retrieve inside of the pipette body, preventing tip jamming. Thanks to this unique, patented system the tip is being sealed with the minimal force and the force necessary for tip ejection is respectively small. The system of retrievable shafts is applied in all multichannel pipettes. The system of precise setting of the tip ejector stroke in other models of HTL pipettes allows ejecting the tip with minimal effort and only after the Minimal movement of the thumb on the ejector pushbutton.
While designing the volume setting system in our variable volume single channel and multichannel pipettes we wanted to make sure that the location of our volume setting knob is proper for convenient one handle operation and that the knob rotates smoothly allowing for precise volume adjustment. Pipette volume can be set precisely with one hand, by the turn of the volume setting knob or pushbutton. Additionally the volume setting knob of DISCOVERY PRO and DISCOVERY Comfort pipettes can be locked. This feature guarantees the reliability of results.

17. HTL Pipettes are renowned for their outstanding accuracy and precision rates. What characterizes our equipment is the fact that it not only performs great when it’s brand new, but it also maintains its superbly reproducible performance after years of usage*. This important advantage is the result of both stringent quality control procedures applied by our QC Department and manufacturing know how gained by us within more than 35 years of pipette manufacturing. From the very initial stages of the designing process, HTL pipettes are crafted to meet the requirement of long lasting reproducibility.
The following features of our pipettes allow us to attain this goal:

  • Ultra smooth pistons
  • Balanced operation forces
  • Low thermal conductivity
  • Unique multichannel manifold

The properties of raw materials applied for the construction of HTL pistons combined with the unique technology of piston polishing result in extraordinary smoothness of this vital component. The smoother the move of the piston, the more repeatable its shape, the more accurate aspiration of the pipette is.
In order to ensure the repeatability of the measurement, it is essential to keep the right proportion between the pipetting force, the blowout stop and the blowout force. On one hand it is essential to keep the operation forces at the lowest possible rate, on the other hoverer it is crucial to let the user feel the right moment when he should stop pressing the pushbutton down, before blowout. The tension of the pipetting and blowout springs applied in newest HTL pipettes is the result of decades of experience. Careful selection of the spring material and their shape allowed us to combine these two necessities in our pipettes. The new construction of the plunger assays applied in above pipettes allows for pipetting with unnoticeable effort, but to feel clear stop between pipetting and blowout at the same time. Thanks to this design the precision of work is easily obtained even by less experienced pipette operators.
Extensive work with some pipettes may result in warming them up from the warmth the hand of the operator. The increase of pipette temperature could cause an accuracy error due to expansion of the air drawing the liquid into the tip. Ultimately the warmer the air, the more expanded the air, the less liquid is aspirated and the larger the error. HTL pipettes resist this negative factor due to the low thermal conductivity of their handles. The material of our pipette components coming in touch with operators’ palms do not worm up as fast as the plastic applied by most of other pipette manufacturers.
In the newest design of HTL multichannel pipettes our engineers made sure that the fact of possessing 8 or 12 shafts does not affect the reproducibility of the pipette. The revolutionary solutions applied in multichannels, ensuring identical aspiration in all multichannel shafts are the alignment of the pistons and the retrievable shaft system. The alignment system guarantees that the plungers in all shafts move with the same paste regardless of the operator’s technique, while the retrievable shafts ensure that all tips are sealed securely without the risk of poor air tightness on the middle shafts.

18. HTL equipment is built to last. HTL pipettes base on well proven constructional concept of the most popular pipettes on the market. The application of solid, but light plastic handle combined with highest grade steel components (calibration screw, springs and low volume pistons) results in high mechanical and chemical durability of our products. There is no pipette which would withstand all chemical and mechanical hazards, but the experience of our dedicated users show that in the most severe environment HTL pipettes shall last longer than plastic or aluminum products of most of other manufacturers.
Breaking shafts is the most common problem faced by all professionals working with the pipettes. When pipette is dropped or swung during tip sealing, the breakage may occur. All versions of HTL pipettes are equipped with the shafts manufactured of PVDF. This space age material guarantees highest mechanical durability of the shaft and lowest durability deterioration under the influence of commonly used aggressive substances. In order to make sure that only shafts of the highest robustness parameters are assembled with our pipettes we introduced a frequent shaft durability test to the range of tests applied during our quality control procedure.

PIPETTE TIPS

1. D/DV & LMP pipettes, models 2-1000 μl:
Ejector removal

  1. Press the tip ejector button.
  2. Turn the ejector bush clockwise (right) to the very end.
  3. Slide the ejector from the plastic arbor.

Ejector assembly

  1. Press the tip ejector button.
  2. Place the tip ejector on the arbor.
  3. Turn the plastic ejector bush counter-clockwise (left) until it’s latched.

Ejector adjustment

  1. Remove the ejector pushbutton.
  2. To increase the ejector length turn the plastic bush to the right.
  3. To decrease the ejector length turn the plastic bush to the left.

Note: Some 10 μl tips may require a use of ejector cap, see the manual.

OP pipettes, models 2-1000 μl:
Ejector removal

  1. Press the ejector pushbutton
  2. Pull down the ejector until released.

Ejector assemble

  1. Place the ejector on the arbor.
  2. Push it in until secured.

Ejector adjustment

  1. Remove the ejector.
  2. Take off the top white spacer H0
  3. Replace it with one of the two sizes delivered in the pipette box.

See user manual for details.
D/DV, LMP & OP pipettes, 5000 & 10000 μl models:
Ejector removal

  1. Remove the tip ejector button
  2. Use the screwdriver to turn the metal arbor counter-clockwise to unscrew the ejector from the arbor.
  3. Release the ejector.

Ejector assembly

  1. Remove the tip ejector button.
  2. Use the screwdriver to turn the metal arbor clockwise to screw the ejector in and adjust its length.

Ejector adjustment

  1. Remove the ejector pushbutton
  2. Use the screwdriver to increase or decrease the ejector length.
  3. After ejector assembly or adjustment, put the ejector button back on its place.
    Note: Some tips may require a use of ejector cap, see the instruction manual for details.

 

2. Although shafts of HTL pipettes are designed to fit all popular tips, the best accuracy and precision results are obtained with HTL tips. The performance of every pipette is checked by gravimetric method and the results of test are printed in pipette Quality Control Certificate.
Some other manufacturer’s tips do fit HTL pipettes, however we cannot assure that our stated performance specifications can be met when other tips are used.

3. Always change tips when you see droplets in the tip, when changing pipettes liquid or the tip has been damaged.

PIPETTE CONTROLLER & SEROLOGICAL PIPETTES

1. The outer body of the SWIFTPET PRO can be cleaning with isopropyl alcohol. Pipette holder,  the nosepiece and micro filter are fully autoclavable at 120°C, 20 min.

2. Pipette controller SWIFTPET PRO has three AAA NiMH batteries, which are accessible by removing the battery cover and can be easily replaced. Please refer to the sticker under the battery lid for details on battery arrangements. In case of long break of using the pipette controller, it’s highly recommended to remove the batteries from the pipette controller or charge the batteries every few months.

3. Full-charge time takes c.a. 7-8 hours. It allows for continuous work for 8 hours. Note! If you use disposable batteries, it is unacceptable to connect the device to the charger.

4. For warranty information please contact your local distributor HTL.

5. No.

6. The negative graduation printed on the pipettes increases the possible pipetting volume of the values nominally indicated on the pipettes. In this way, if the nominally indicated volume of the pipette is exceeded slightly it is not necessary to use the next largest serological pipette, but rather an accurate pipetting process can be carried out with the pipette currently in use.

REPETITIVE DISPENSER Minilab 201 & SYRINGES

1. No.

2. Yes, it can be autoclaved.

3. Yes, please refer to this page