The accuracy and repeatability of the pipette. For most customers, it is difficult and unnecessary to check pipette performance before purchasing.
But there are two points to explain here: First, do not easily believe the seller’s verbal promises, and be sure to check the written materials provided by the manufacturer; second, understand the supplier’s after-sales service when purchasing, as well as replacement parts, maintenance, and repair Happening.
2. Durability/maintenance: the pipette has a long service life, requiring little maintenance or low maintenance cost
This mainly depends on the material used in the pipette. For the piston, there are mainly three materials of stainless steel, ceramic, and plastic.
Of course, high-quality materials often mean higher prices, so you need to consider the factors of the purchase price and life span.
3. In line with ergonomic principles: comfortable hand feel, light suction and discharge operation force, avoid repetitive muscle strain, small suction head force
The main considerations are as follows:
First, compare the pipettes of the same volume to complete a discharge (must be pressed to the end). Pushing the thumb is the key to comfort. The less the pressure means the lower the risk of finger injury caused by long-term use. Second, the less effort is required to load and unload the tip, the better. Third, other auxiliary designs, such as the frosted design of the shell and the finger hook design, help to further improve the comfort.
Precautions for the use of pipettes
When sucking liquid, you must release your thumb slowly and steadily. Do not release it suddenly to prevent the solution from being sucked into the liquid extractor too quickly to corrode the plunger and cause air leakage.
In order to obtain higher accuracy, the pipette tip needs to pre-absorb the sample solution and then formally aspirate the liquid, because when the serum protein solution or organic solvent is sucked, the “liquid film” layer will remain on the inner wall of the sample.
The pipette tip, resulting in a small discharge volume and error. High concentration and high viscosity liquids can cause errors. In order to eliminate the error, the compensation amount can be determined through experiments.
The compensation amount can be set by using the adjustment knob to change the reading of the reading window. The liquid extractor can be calibrated by weighing pure water with an analytical balance and calculating it. The weight of 1mL of distilled water at 20°C is 0.9982g. The method of repeatedly tapping the pipette tip to tighten is very undesirable. Do not pipetting when the pipette is not equipped with a tip. When setting the range, go to the desired range.
These numbers are clearly displayed in the display window. When the setting range is within the range of the pipette, do not move the button out of the range, otherwise, it will block the mechanical device and damage the pipette.
Strictly prohibit the pipette from absorbing highly volatile and corrosive liquids (such as concentrated acid, concentrated alkali, organic matter, etc.). Never use a pipette to pipetting and mix liquids. Do not use a wide-range pipette to pipetting a small amount of liquid, so as not to affect accuracy. At the same time, if you need to pipette a large amount of liquid beyond the measurement range, please use a pipette.