What Is and How to Choose Non-Sterile Pipette Tips

 Non-sterile pipette tips are an indispensable tool in the hands of experimenters. Appropriate pipette tips can not only reduce the loss of pipettes but also improve the accuracy of experimental results. Here are some introductions to these non-sterile tips.

Non-sterile Pipette tips size:

• In general, in most lab consumable supplier companies, such as Hawach company, supply the volume of non-sterile tips is 10µL, 200µL, 300µL, 1000µL, etc.
• And different specifications of non-sterile tips have different lengths and calibers, but some of the same specifications of these pipette tips have exactly the same length.

Material:

• Tips with non-sterile are disposable consumables that come into direct contact with liquid samples and are made with PP material.
• And without a plasticizer release agent to the otherwise soluble matter will affect the experimental results

Feature of Non-sterile tip:

• No RNA, DNase, no heat source, ensure the integrity of the sample when moving, no pollution, no denaturation.
• Using USP-Class VI standard polystyrene raw materials, GMP100,000 clean workshop production
• And with a smooth inner wall, high-temperature resistance, less residual liquid
• In Hawach, supply bulk package packaging to meet customer needs
• And effectively avoid cross-contamination between samples caused by aerosol to match the pipettes of various brands and models on the market
• Especially tips with non-sterile can save the number of samples and reagents and improve the accuracy of experimental operations
• Adapt to the absorption of various organic solvents, and various pipettes
• The product complies with the country’s health standards and has passed the certification with no cytotoxicity, pyrogen-free.
• And the inner wall is smooth without flow marks, and the tip has no notch burrs, otherwise, it will lead to inaccurate drainage
• In addition,  material. At present, the tips with non-sterile on the market are basically made of polypropylene plastic (a colorless and transparent plastic with high chemical inertness and a wide temperature range).
• However, people usually make non-sterile pipette tips in different kinds of polypropylene: high-quality tips are often made from natural polypropylene, while cheaper tips may use recycled polypropylene plastic
• Pipette tips with non-sterile will not affect the accuracy of the pipetting results

Application:

• Designed non-sterile pipette tips for a variety of pipetting applications in molecular biology, cell culture, clinical laboratories, and more.
• The most commonly used type of tip is the non-sterile. And used in laboratory applications where sterility is not critical to the experiment or test being performed.
• In addition, widely used in molecular biology, gene sequencing, bioengineering, medicine, hospital clinical testing, and many other fields.
• Sterilized tips are usually boxed to prevent contamination. The concept of sterility refers to the absence of contamination from other microorganisms, such as fungi, bacteria, etc., the most difficult spores to discharge, unsterilized is the opposite
• And used for the experimental that avoids the presence or dissolution of fo reign biological contaminants to directly affect the analytical results

How to choose the  Non-sterile Pipette tip :

1. Weigh the sample volume

After rinsing the tips, repeat the sample loading procedure several times, weighing the sample each time and recording the reading. Calculate pipetting precision after converting test solution density to volume

2. Outer packaging inspection

The packaging should be intact and clearly marked.

3. Tip detection

• Check whether the suction head is deformed or damaged, and use a suitable sampler to suck up an appropriate amount of liquid to see if there is air leakage, suction hole blockage, or air leakage.
• After excluding the pipette factor, if there is any abnormality, that is, the batch of tips does not meet the experimental requirements of this laboratory.

 

There are also introduces about the function of disposable pipette tips, what is sterile filtered pipette tips, etc.

4 Ways to Choose Best Glass Fiber Filter Membranes

 As we all know, glass fiber filter membranes are laboratory filtration consumables, which have the characteristics of a high flow rate and strong dirt-holding capacity and are mainly for deep filtration. Today, here are some ways to choose them.

How to choose a glass fiber filter membrane:

1. According to size

• Domestic basic filter membranes are divided into fast, medium, and slow.
• Divided into finer ones, which generally have corresponding pore sizes, such as fiber filter membrane, the aperture: 0.45μm, 1.0μm, 1.6μm;
• Diameter: 13mm, 25mm, 47mm, 50mm, 60mm, etc;

2. Purity of material

• The quality of the filter membrane mainly depends on the purity of the cotton fiber, and it is best not to have additives.
• Glass fiber material filter paper is 99.90% glass fiber material.
• In addition, glass fiber filter paper has the characteristics of a high flow rate, strong dirt-holding capacity, and can filter fine particles.
• And compared with other fiber materials and man-made materials, glass fiber material filter paper has higher filtration efficiency and stronger dirt-holding capacity.
• Because most of the basic glass fiber filter paper does not use any additives, it is just curled glass microfibers, so it is very pure.
• But because of this, should pre-wash to avoid not to remain in the filtrate in the microfibers, and should add a surface filter under the glass fiber.

3. According to usage

• There are many types of surface filtration membranes, which are hydrophilic and hydrophobic (there are also some hydrophilic and hydrophobic dual-purpose membranes).
• In short, hydrophilicity is more suitable for filtering aqueous solutions, but not for filtering organic solvents, acid-base solutions, and air; hydrophobicity is suitable for filtering organic solvents, acid-base solutions, and air.
• But in fact, depending on the filter material, they have different characteristics.

4. Polypropylene vs. glass fiber membrane

• If it is general ambient air sampling, not sampling under high-temperature conditions, should not recommend trying a glass fiber membrane.
• High-throughput polypropylene fiber membrane, suitable for large-flow sampling
• Good hydrophobic performance, not easy to absorb water vapor in the air, good constant weight performance after repeated heating, can save repeated heating process
• Small resistance, high capture efficiency
• High strength, basically no shedding of fibers
• Simple pre-treatment and strong operability
• And should recommend to use 1.0um polypropylene membrane, 0.3um>99.95%

Some tips about using glass fiber filter membranes:

1. What should I do if the glass fiber membrane is broken during filtration?

• The reasons for the rupture of the filter membrane: one is that the material cannot withstand the dissolution of the sample solvent
• And the other is the pressure that the ultrafilter can withstand during filtration.
• Then the corresponding solution is to choose a filter membrane that is resistant to the sample solvent and apply the appropriate pressure
• And especially when using a filter with a smaller diameter (for the pressure resistance of the filter, please refer to the corresponding COA).

2. What should I do if the flow rate is too slow to affect the efficiency when filtering the sample?

• When the flow rate is too slow, we need to determine whether the sample contains high particulate matter and whether the sample viscosity is too high.
• In this case, high-speed centrifugation can be performed to remove particulate matter
• And an appropriate solvent can be selected for dilution, or a filter with a larger diameter can be used.

3. What is the difference between glass fiber filter paper and conventional nylon and other microporous membranes?

• From the perspective of filtration mechanism, glass fiber filter paper is a deep filter, which is characterized by trapping particles on the surface and in the medium matrix at the same time.
• It has the characteristics of deep filtration, fast flow rate, and large loading capacity;
• While the thickness of microporous filtration membranes such as nylon is relatively thin, and it tends to surface filtration.

What Is HAWACH MCE Gridded Filter Membrane

   MCE gridded filter membrane in Hawach company is made of mixed cellulose ester with a high-contrast grid for easy identification and counting. It is suitable for the sampling and monitoring of particles and fibers in the gas.

Brief introduction:

What Is HAWACH MCE Gridded Filter Membrane：

• Thicknes:85 – 100μm
• pore size : 0.22μm, 0.45μm, 0.8μm
• Diameters:47mm, 50mm
• pH Range: 3.5 – 8
• The MCE gridded membrane has a high internal surface area porosity for better product adsorption.
• Chemical Compatibility: Ideal for aqueous-based samples
• They are naturally hydrophilic, biologically inert, and have good thermal stability up to 90 °C.

Features:

• Extremely uniform membrane pores
• A variety of apertures to meet different needs
• And with low biosorption
• Good biocompatibility
• Wide range of sizes and accuracies
• White background with black or green grid
• And made of pure MCE material, with no support
• Extremely uniform aperture with low background
• It is a porous membrane filter material made of refined nitrocellulose, adding the appropriate amount of cellulose acetate, acetone, n-butanol, ethanol, etc.
• It has a smooth surface, light and thin texture, high porosity, uniform microporous structure, and fast flow rate
• And not easy Adsorption and other characteristics.
• These membrane filters offer distinct advantages, including ease of handling, lower risk of accidental membrane contamination, less care
• And skill required to aseptically separate the membrane from the package, and reduced testing time.

Usage of  Hawach MCE Gridded Filter Membrane:

• Pharmaceutical industry: used for water injection, large infusion solution, pre-crystallization particle, bacterial filtration, vaccine serum, tissue culture, etc.
• Electronics industry: used for air purification of semiconductor devices and integrated circuit workshops, preparation of high-purity water for washing, and purification of solvents, etc.
• Daily chemical industry: used for particulate filtration of oil-containing solutions in daily cosmetics.
• Public health: used for drinking water filtration, bacterial filtration inspection of river pond water quality, and dust particle filtration inspection in working areas.
• Food industry: sterilization of beverages, juices, wines, oils, etc.
• And used for sterility inspection – membrane filtration method and analysis and determination in other scientific research.
• Used for colony counting, particle testing, and microscopy.
• White membranes with black grids are available in individual sleeves or in strips of 100 for use with standard auto-feed equipment.
• In addition, sterile black membrane filters with white grids are also available individually wrapped.
• And widely used membranes for analytical and research applications. Especially suitable for aqueous solutions. This membrane is also commonly used in contamination testing.

What Are Tecan Automation Tips and about Features

 Tecan automation tips are made of imported medical-grade polypropylene (PP) material with special surface treatment. And has the characteristics of high precision, high transparency, and good hydrophobicity.

The volume of  Tecan automation tips:

•  Volume of Tecan conductive tip: 20μL, 50μL, 200μL, Tecan 1000μL tips;
• Hawach conductive pipette tip companies, all volumes of Tecan tips are suitable for TECAN, Hamilton automatic pipetting workstations

Feature of  Tecan automation tips:

•  Sterilized production in a 100,000-level dust-free workshop without chemical residues.
• Uniform conductivity: The product has passed the conductivity test to ensure that the product has uniform conductivity, strong hydrophobicity, and does not hang on the wall.
•  Strong adaptability: self-owned mold company and R&D team, structural mapping according to the original adapter, mature injection molding process
•  In addition, advanced production equipment ensures a high degree of adaptability between products and automation equipment.
• Effectively prevent cross-infection: the super-hydrophobic high-quality filter element is used, and the product has passed the leak test and insertion force test to ensure that the product has good verticality and sealing
• And all volume: Tecan 1000μLTips are mainly for the Tecan pipetting workstation platform with eliminates the risk of cross-infection
• The Tecan series of pipetting tip molds produced by Hawach with new nano-processing technology greatly reduces the size of the tip. surface adsorption.
• Like Tecan 1000μLTips, Hawach company provides Tecan series pipette tips in various volumes
• Made of conductive polypropylene, for capacitive liquids bit detection
• And verified the accuracy of the suction head to ensure product quality and performance.
• Reducing sample waste and reagent waste
• And minimizing damage is especially important when trying to get the most out of precious reagents and when working with rare samples.

Application:

• Tecan tips are commonly for preventing pipette contamination and sample cross-contamination.
• And no need for plumbing homemade to prevent contamination. Plain conductive tips without filter elements are also popular.
• Mainly used on the Tecan pipetting workstation platform, the Tecan series pipette tip molds produce new nano-processing technology, which greatly reduces the surface adsorption of the tips.

Hawach Tecan Tips produced aims:

• Reducing volume and saving costs is the constant mission of every enterprise: the drive to produce more samples also creates a need to reduce sample waste and reagent waste.
• And optimized assays and reduced volume saving on reagent and sample usage costs.
• Minimizing damage is especially important to us when trying to get the most out of precious reagents and when working with rare samples.
• The adoption of small-volume pipetting in the automation of liquid handling processes certainly brings all of the above-mentioned scale and cost advantages.

There are more introduces about pipette tips: how to install pipette tips, what is a function of disposable pipette tips, etc.

Microporous Filter Membranes Introduction

 In the lab filtration process, a filter membrane is required. The material and type of filter membrane sometimes have a great influence on the sample, and different filter membranes need to be screened. The following briefly introduces the microporous filter membrane.

Microporous Filter Membranes Introduction:

 

Definition of microporous membrane filter:

• The membrane separation process is a method of separating mixtures using a thin film.
• As a selective pass-through phase between two phases, the membrane can allow one or more components in the two phases to pass through the membrane and retain other components, so as to realize the separation between different components and achieve separation, concentration, and purification.
• It mainly uses the fluid pressure difference as the driving force for the screening and separation process. Microfiltration, reverse osmosis, nanofiltration, and ultrafiltration are all pressure-driven membrane separation technologies.

Microporous filter membrane material：

• Microporous membranes filter material mainly include cellulose acetate membranes, mixed cellulose ester microporous membranes, nylon membranes
• And polytetrafluoroethylene membranes, polyvinylidene fluoride membranes (PVDF), polyethersulfone membranes, and PP filter membranes.

Microporous Filter Membranes Pore Sizes:

1. What are the differences in the pore size of the microporous membrane?

• Nominal microporous membrane pore size ratings are provided as a general indicator of membrane retention.
• It is understood that some particles larger than or equal to the nominal pore size will pass through the filter membrane and enter the filtrate.
• Some manufacturers may relate a nominal pore size rating to a percent filtration efficiency.
• Nominal pore size grades vary by manufacturer and therefore are not necessarily the same.
• Filters from manufacturers with similar nominal pore size ratings may not exhibit similar retention characteristics.
• Pore size ratings are often based on retention studies using standard microbial cultures or challenging suspended particles of known size.
• The pore size rating indicates the size of the small microorganisms or particles retained in these studies. Pore ​​size ratings are almost always related to bubble point specifications used for quality control during membrane manufacturing. Most pore size grades, especially those based on microbial retention, are comparable between manufacturers.
• There is more uncertainty in pore size classes based on particle retention studies, especially for pore size classes < 0.2 µm, as there are no standard methods for these studies.
• And regardless of pore size, it is important to understand that conditions of use do affect particle retention. Even a filter with a nominal pore size can operate at the condition of allowing particles larger than the expected size to pass through.

2.Common pore sizes are 0.22μm, 0.45μm, 0.8μm, 1.0μm

a.0.22μm:

• It can remove the requirements of extremely fine particles in samples and mobile phases; meet the requirements of GMP or Pharmacopoeia, and the sterilization rate reaches 99.99%.
• It is suitable for the treatment of solvents and samples with high requirements such as ion-pair reagents and ultra-pure chromatography. Filtered water, mass spec solvent samples, etc. Applicable to packing chromatography systems smaller than 3μm, 3μm, or larger.

b.0.45μm:

• It can filter out most bacteria and microorganisms, is suitable for routine sample and mobile phase filtration, and can meet general chromatographic requirements

c.0.8μm, 1.0μm

• And can remove most insoluble particles, suitable for analysis and detection of relatively low sample content

Brief Introductions of PH Test Papers

 PH test papers are a “ruler” to test the pH of a solution, also called litmus paper. And have many kinds, such as pH health test strips.

 

What is pH test paper:

• There are three indicators of methyl red, bromocresol green, and thymol blue on the PH test papers, and they will change color according to certain rules in solutions of different pH values.
• PH test papers are popular. When testing the pH of the solution, use a clean and dry glass rod to test the liquid
• And drop it in the middle of the test paper, observe the color after the change is stable, and compare it with the standard color chart to judge the properties of the solution.
• When testing the pH of the gas, first wet the test paper with distilled water, stick it to one end of the glass rod
• And then send it to the mouth of the container containing the gas to be tested, observe the change of color, and judge the nature of the gas.

 What do ph test papers for:

Method 1: Detect the pH of the liquid

Preparation tools: test paper glass rod

1. When you need to test the pH of the solution, take a small piece of test paper on the watch glass or glass, and be sure to use a clean glass.

2. Then use a clean and dry glass rod to dip a little of the liquid you need to test on the middle part of the test paper.

3. It does not take a long time to observe his changes. After the color is stable, you can compare it with the standard colorimetric card
4. And then judge whether the solution is acidic or alkaline, that is, the nature of the solution.

How to use ph test papers:

Method 2: Detect the pH of the gas

Preparation tools: test paper distilled water glass rod

1. First, you need to use distilled water to soak your PH test paper strips, and then stick it to one end of your glass rod.

2. Send it near the mouth of the gas container you need to test.

3. After a while, you can observe his changes, and judge the nature of the gas according to his changes. The editor here reminds us that the test paper should not touch the edge of the container’s mouth.

What is the principle of pH test paper:

• The prototype of pH test paper, litmus paper, was discovered by Boyle by chance:
• During a tense experiment, splashed the violets in the laboratory with concentrated hydrochloric acid.
• Boyle, who loves flowers, hurriedly rinsed the smoking violets with water and put them in a vase.
• After a while, Boyle noticed that the deep purple violets had turned red. This strange phenomenon prompted him to conduct many experiments on the interaction of flowers and trees with acids and bases.
• From this, he found that most flowers and plants can change their color under the action of acid or alkali.
• Among them, the purple infusion extracted from litmus lichen is the most obvious.
• It turns red when it encounters acid, and blue when it encounters alkali.
• Taking advantage of this feature, Boyle soaked the paper with litmus infusion, and then baked it, which made the acid-base test paper commonly used in experiments – litmus paper.
• And there are three indicators on the ph test strips: methyl red, bromocresol green, and thymol blue. Methyl red, bromocresol green, thymol blue.
• And phenolphthalein will change color according to certain rules in solutions of different pH values.

There are more introduces about other products, like the material of centrifuge tubes, type of centrifuge tubes, etc.

Brief Introductions of Pasteur Pipettes

 Pasteur pipettes are made from selected medical grade LDPE raw materials and are suitable for small volume pipetting. Optimized surface tension for more fluid flow and easier handling.

Brief introductions of Pasteur Pipettes:

 

What is a Pasteur pipette:

It is a glass tube with two open ends (usually about 5 mm inside diameter). The tube is thinner at one end and has a smaller inner diameter (less than 1mm and has a glue tip at the other end). It is mainly for non-steady-state transfer of liquids, however, often “corrected” by calculating the number of droplets transferred per ml of fluorine, e.g. the ratio of droplets/mL is about Q.U2 ml/decreased.

How to use pasteur pipette:

Pasteur pipette uses by inserting the docking end of Pasteur pipettes with a cotton plug before use and then sterilizing the pipettes so plugged, that the transferred liquid can avoid microbial contamination. In microbiology research, graduated tampons can also block (analytical) pipettes for the same reason.

Features:

1. Good transparency, with tick marks, easy to observe;
2. It has certain elasticity and plasticity and should bend at a certain angle, which is conducive to entering the micro-container for liquid extraction or liquid addition;
3. Good elasticity, not easy to break, suitable for quick pipetting. Easy to use, accurate and reliable, good repeatability of drop volume;
4. Disposable Pasteur pipette ends are heat sealable for conveying small quantities of liquids;
5. Light weight, compact structure, easy to use, low consumption of consumables, one-time reduction of raw material pollution during use;
6. Smooth and transparent, reducing liquid adhesion, good elasticity, easy pipetting, accurate scale;
7. Small tips ensure repeatability of drops; tube ends can be heat-sealed to easily carry liquids;
8. The infusion tube body is translucent and bright white, with the ideal liquid flow on the tube wall and strong controllability;
9. Disposable sterile straws are slender, flexible, and bendable for easy access to micro or special containers;
10. Often used for operations such as absorbing, transferring, or carrying small amounts of liquids;
11. The tube body is translucent and bright white, the wall fluidity is ideal, and the controllability is strong;
12. The tube body is slender and soft, bendable, and easy to enter and exit traces or special containers;
13.  Sterilization method: ethylene oxide EO disinfection and sterilization.

Notice about Pasteur Pipettes:

• In addition to the cost, various conditions should be considered when using plastic as a reaction vessel, similar to heating and refluxing strong corrosive solvents, whether the plastic can accommodate it
• And should affect the process no matter if there are residual additives, then it will dissolve in the solvent, etc.

There are more introduces about other products: adjustable pipettes use, how to disinfect a pipette, etc.