Using gloves, lab-coats and hoods does just that. Use your lab-coats only inside your cell culture lab and have them cleaned often. Make sure your hood is serviced often to guarantee that it is properly working. Having a hood is not enough to ensure a sterile environment: you must use it correctly. First, make sure that you are not blocking the flow of air inside the hood: do not place material over the air outlets or inlets that are often found at the front and back of your bench space inside the hood. If you use a tray of water inside the incubator, change the water often. You might sometimes need to add a chemical to the water to prevent contamination (always check that this chemical is compatible with the material your tray is made of). Spray your gloves and everything that you bring inside the hood with ethanol. Since so much effort is dedicated to maintaining a sterile environment inside the incubator and the hood, make sure that you minimize the time cells spend outside of these environments.
When an experiment is designed, the choice of pipettes, pipette tips, and the pipetting procedures receive little attention. Aseptic technique is the only way to achieve reliable and reproducible results. Contamination affects cell growth, metabolism, and well-being – the exact things scientists are interested in studying. Contaminated cell lines don’t have the desired characteristics and they function differently each time, depending on the severity of contamination. Also, you might end up studying the wrong organisms if contaminants overgrow your cells of interest. First off, good laboratory practice and careful planning of the work steps. Making sure to only keep the things you need for the specific workflow in the laminar flow cabinet and working with one cell culture at the time. Also, regularly testing for contaminations like Mycoplasma gives you peace of mind to trust your results. When working aseptically, money spent on pre-sterilized filter tips and sterile reagents is money well spent.
Within the scientific community, a rising number of experiments published cannot be reproduced by other groups. Incorrect pipette handling (e.g. holding the pipette at an angle during liquid aspiration) may be one reason for this. A second source of error often not taken seriously is plastics. Consumables may lead to problems with analysis results, e.g. due to leachables, as well as incorrect pipetting volumes. This may result in non-reproducible data if experiments are repeated by other groups using other consumables. Some problems with pipette tips are obvious like: Tips have to be pushed powerfully onto the pipette cone in order to achieve efficient tip fit Banana-shaped tips make it difficult to fill a plate with multichannel pipettes Pipetting of volumes below 1 µL on a solid surface is impossible because the liquid drop sticks to the outside of the tip.
Three dimensional (3D) cell cultures have been an area of increasing interest and relevance across several research fields including drug discovery, developmental biology and stem cell-based therapies. However, handling 3D structures can be difficult. In particular, the replacement of liquid media and reagents in which liquid is removed using pipettes is difficult to perform as the 3D spheroids can be easily aspirated into the pipette tip. This novel pipette tip is suitable for high throughput screening and automation and will revolutionise the techniques used for the production and analysis of 3D spheroids.
Poor pipetting technique causes low reproducibility between samples and experiments (Hawthorne et al., 2019, and Lippi et al., 2017). Preparing 3D cell cultures is challenging and prone to variability due to the hydrogels, pipettes, and tips used in the process, but most importantly due to individual pipetting practices. With electronic pipettes, you can use protocols with fixed pipetting speeds and mixing steps, consequently minimizing the variability introduced by individual pipetting practices. Here, we show that you can achieve very reproducible 3D cell culture results with electronic Picus® Nxt pipettes and GrowDex® hydrogel.
Open the pipette, immerse the parts in a detergent solution, such as Deconex® 12 Basic. Rinse well with distilled water and allow to dry. DNA can be eliminated by immersing pipette parts in at least 3% (w/v) sodium hypochlorite for at least 15 minutes (2,3). Rinse well with distilled water and allow to dry.
Non hazardous micropipette tips can be collected for recycling. Collect in a puncture proof container. BL1 and BL2 tips must be decontaminated with bleach or alcohol before being deposited into a recycling bin. Pharmaceutical contamination would also prevent recycling of tips.
The first reagent in a tube. Then you can use the same tip to add your primer/master mix solution to your eight different PCR tubes. In this example, you can reduce the use of 16 pipette tips down to just 3! Then, use a new tip each time that you add a DNA sample to your different reactions.
The filters prevent aerosols from reaching the pipette body and potentially contaminating subsequent samples. Always change the pipette tip after each sample. Regularly autoclave, or disinfect, the pipette or the components that may come into contact with the sample.