Four essential instruments for membrane test in microbiological examination in water
Four essential instruments for membrane test in microbiological examination in water
The membrane method is a microbial inspection method in which microporous membranes are used to intercept microorganisms in liquid samples and culture directly on the membranes; it has been widely used in the pharmaceutical industry, environmental monitoring, food industry, and other fields at home and abroad.
At present, it is only included in the "GB/T8538-2008 drinking natural mineral water test method", "GB/T5750.12-2006 standard test method for drinking water", "People's Republic of China Pharmacopoeia" (ChP) 2010 version and other beverage industry related In the standard. However, compared with other microbiological testing methods, the filter membrane method has a wider application range and is not easily interfered by bacteriostatic substances. In the future, the industry using the membrane method for microbial detection will be more and more. The main methods used in the membrane method include: membrane filter, microporous membrane, vacuum pump, petri dish 90mm × 12mm, toothless tweezers, constant temperature incubator and other instruments. The instrument that is actually needed for the sophisticated membrane membrane method is a necessary prerequisite for the precise detection of microorganisms by the membrane method. The following is a detailed description of the requirements of the filter method for each instrument:
1. The premise of the membrane filter is based on the principle of the membrane membrane method. Based on this, a careful and scientific design is carried out to further solve the actual demand of the membrane membrane method. If the materials used must be strong and durable, they have no inhibition or promotion to microorganisms; the design is more conducive to sterilization and disinfection, and easy to operate.
Guangdong Huankai's new generation of stainless steel membrane filter (MFS-3A-250-K) is an excellent product that can meet the requirements of the membrane method. The whole machine is made of high-quality 316 stainless steel, which is durable and has no effect on microbial growth. It adopts quick-connect design, the whole machine is detachable, which is conducive to high-pressure steam sterilization of the whole machine; modular design, multiple connectors are available, Single or multiple sample colleague filtration, adapt to stainless steel filter cup and plastic filter cup two kinds of filter cups; patent "three-claw" design, one-handed can complete the filter bowl or filter pick and place.
2. Vacuum pump, but with the oil vacuum pump, the oil-free vacuum pump has higher cleanliness, which is more conducive to improving the accuracy of the test results. At present, there are many types of vacuum pumps on the market. Oil vacuum pumps have basically been replaced by oil-free vacuum pumps; the more advanced ones are diaphragm gas-liquid dual-purpose vacuum pumps, which do not require the transition of the liquid storage bottle, and the liquid is directly discharged through the pump body, reducing manual operation. The high-quality gas-liquid dual-purpose pump has a ring-shaped szkb series SZKB-3A/3B/3C gas-liquid dual-purpose vacuum pump with a vacuum of up to 900 mbar.
3. Microporous membrane microporous membrane is the key to the accuracy of the test results. In GB/T 8538-2008 Standard for the Detection of Drinking Natural Mineral Water, the filter is required to be a water film with a diameter of 47 mm and a pore size of 045 um. The non-sterilized filter membrane needs to be sterilized for about 1 hour before the experiment: the filter membrane is placed in a beaker, distilled water is added, and the mixture is boiled and sterilized 3 times in a boiling water bath for 15 min/time. After the first 2 times of boiling, the water needs to be replaced and washed 2 to 3 times to wash the residual solvent. The non-sterilization filter has a long pretreatment time. Therefore, the GB/T 8538-2008 drinking natural mineral water test standard and other standards recommend using a sterile filter to carry out the experiment.
4. Fully automatic filter dispenser The sterile filter membrane is packaged separately and can be used only by tearing the package before each use. Here, the experimenter must keep his hands clean. Otherwise, the sterile filter will contaminate the microorganisms left on the operator's hands, thus affecting the experimental results. In response to this situation, the domestic product has been developed to deal with this situation - automatic filter dispenser. Domestically, only the ring company has developed this product. This instrument simplifies the steps of shredding packaging. It is equipped with an infrared sensor. The experimenter can automatically release the film only through the infrared sensor without touching the instrument button, reducing the possibility of microbial contamination. Sex.
The above is the key instrument for obtaining accurate and reliable results in the microbiological examination of beverages, but the advanced instrument also requires standardized operation. It is hoped that all experimental personnel will master the necessary detection technology!
40m Laser Distance Meter is a functional and advanced measuring tools, no need climbing up and down, which is the engineers' best friends. No matter you have your own brand or not, JRT can help you to start with laser range finder business. JRT sold more than 1 million OEM laser distance meter modules last year, and we will triple or fifth times of that quantity.
We accept OEM/ODM and customized product.
>1. Logo printed customized: at the back of the instruments etc.
>2. Distance customized: 40m, 60m, 100m, 150m.
>3. Package box customized
Distance Measure Meter,40M Laser Distance Measure,Laser Distance Meter 40M,40M Laser Distance Meter
Chengdu JRT Meter Technology Co., Ltd , https://www.rangingsensor.com