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Everyday, a variety of antiseptics are used to control and/or kill microorganisms. Hospitals disinfect areas using strong chemicals such as sodium hypochlorite, which is identical to houshold bleach. Doctors and nurses use alcohol to swab areas where a needle will be injected. Betadine is used on skin prior to surgeries to ensure that bacteria does not cause infection. Municipalities use chlorine to prevent the spread of bacteria in drinking water and chemical agents are added to food to prevent spoilage. Antiseptics are agents that inhibit or kill microorganisms on living tissue while disinfectants are more harsh and used on non living objects. Some disinfectants are referred to as sterilants or sporocides, which mean they destroy all microbial life including endospores. Ethylene oxide is an example of a sterilizer that is used to sterilize objects that can’t be exposed to high heat. Sanitizers, such as those used in the food industry, reduce microbial numbers to safe levels but do not eliminate all microbes. Agents that are bacteriostatic inhibit the growth of bacterial cells but do not kill them.
With winter behind us and summer just around the corner, we all know what the means, It’s Bar-B- Que Time! Noting better than a sunny day in the backyard with a cold drink in your hand and the smell of your favorite meat and veggies on the grille.
But we’ve all been made aware of how important it is to insure that steak or turkey burger has been cooked to a propper temperature. With the disappearance of Mercury Thermometers from most states, we now have many digital thermometers to choose from.
I personally like the fact that they will provide you with an accurate reading within roughly 1 second. They range from some simple models, as pictured above and to the right. Or for those of us who are looking for more state of the art, high tech models, you now have the option to purchase a non-touch, laser-pointer digital thermometer, which I’m contemplating so that I can impress my in-laws, despite my wife rolling her eyes.
The important factor is making sure that whatever your grilling, is thoroughly cooked. The turkey burgers I grilled last night suggested an inside temp of 165 degree’s. The models I have been looking at all share pretty much the specifications and features:
- Temperature in °C and °F
- Stainless Steel Probe and No-Contact Infrared Option
- LED Indicators for HACCP Zones
According to Wikipeadia: Every year in the United States, 6.5 million to 33 million cases of illness are diagnosed due to microbial pathogens, with about 9000 deaths occurring annually as well. According to a multi-state study published in the America Journal of Preventative Medicine, the annual cost of disease caused by food borne pathogens is estimated to be anywhere from 9.3 to 12.9 billion dollars in “medical costs and productivity losses.” Most of these diseases come from contact with contaminated raw meat, although other “vehicles of transmission” are becoming more and more frequent due to global travel. Other sources of disease-causing pathogens can include, but are not limited to: lettuce, sprouts, fruit juices, vegetables, raw milk and water. However, the main source of disease caused by microbial pathogens is usually raw meat. The type of pathogen present varies depending on the type of meat eaten. For instance, the most common pathogen found in beef is Escherichia coli O157:H7, while Salmonella serovars are more common in poultry.
As always, we encourage you to call our knowledgeable Laboratory Sales Staff are here to assist you and answer any questions that you may have.
I decided to talk about Sterilizers for this weeks blog. So, what exactly does a sterilizer do? You’re probably thinking, really? It sterilizes, right? But admittedly, having never used one personally, I thought I would get the facts. I happen to choose the Market Forge Sterilmatic® for a couple of reasons. The fact that they’ve been in business since 1896 indicates that they must make a good product and obviously know what they’re doing. In speaking with one of their representatives, I was quite impressed with her product knowledge and impressed to learn that the average years of employment at Market Forge is 25 years. Lisa is actually a newby as she only has 12 years with the company.
But getting back to what the Sterilizer (Autoclave) does, for starters, you would typically find a sterilizer in laboratories, veterinary clinics and processing plants. Sizes vary but the one pictured above is 18-3/4″ X 27-5/8″ X 31″. The unit has a self-sealing door which cannot be opened until the steam pressure is completely exhausted. Operational temperature is up to 250 F (121 C) and is fully automatic. The Pressure will be automatcially exhausted and the power supply will shut off at the termination of the cycle. Temperature is adjustable from 230 F – 250 F.
The unit has been designed to work with several power sources including 208 – 240V 1 phase or 3 phase.
Note that optional accessories include tubular leg stainless steel stand with shelf, second shelf, perforated trays and wire basket. Also, if your lab does not have the capabilities of exhausting steam to the outside, you will need the Exhaust Condenser.
As always, our knowledgeable staff here at OpticsPlanet will be happy to assist you in configuring the right sterilizer for your application. Your feedback and comments to this blog as welcome.
The Kirby Bauer method is a laboratory technique used to determine the efficacy of a given antibiotic or antimicrobial agent. Paper disks containing specific concentrations of the antibiotic or antimicrobial agent are placed on the agar surface containing a lawn of bacteria. The chemotherapeutic agent then diffuses out, forming a concentration gradient. If the agent kills the test organism, there will be a zone around the disk where no growth occurs called the zone of inhibition. The zone of inhibition varies with the diffusability of the agent, the size of the inoculum, the type of medium, and many other factors. The recommended medium in this test is Mueller-Hinton II agar. Its pH should be between 7.2 and 7.4 and it is poured to a uniform thickness of 4mm in the petri plate. Innoculation of the medium is performed with a cotton swab from a broth culture. High potency disks are used that may be placed on the agar with a mechanical dispenser or sterile forceps. After 16-18 hours of incubation the discs are measured to the nearest millimeter and compared to each other.
For this weeks blog I thought I’d bring up the topic of Ear Plugs, or is it better to refer to it as hearing protection? I guess if it’s my wife chasing me with a list of things to do around the house, you can’t really call it hearing protection. But all kidding aside, they do serve a purpose.
Ear Plugs as compared to Ear Muffs are pretty much made using a foam material, which makes it pliable to fit a majority of ear canals. I’m sure we all understand that no two ears canals are alike. As pictured above, they are available both with and without cords. The pair to the right, which are distributed by Sperian / Honeywell are color coded. Yellow for smaller ears canals and coral for larger. Pre-shaped foam earplugs feature a smooth outer skin for maximum user comfort and being made of foam, the are disposable, nonirritating and non-allergenic.
For those of you who prefer a reusable ear plug, Howard Leight offers a set of plugs (pictured to the right) available with and without a cord, that featurers an advanced air pocket design with internal noise-blocking fins. The four-flange profile creates better seal in the ear canal with the comcerpt of less pressure in the ear canal and to eliminate that “plugged up” feeling. The rounded flanges, tapered shape fits better in the ear canal and the firm stem facilitates easy insertion and removal. So for all you weekend warriors out there with your lawn mowers and grass trimmers, you have several choices to save your hearing. Unfortunately, it will not totally block out your spouse. Oh, and if my wife happens to read this, Just Kidding Dear.
Your comments and feedback are welcome.
Laboratory notebooks are designed in accordance with GLP. Lab notebooks in the research laboratory must be auditable and are considered a legal document. Laboratory notebook paper must be acid free for long term storage. Lab notes must be able to be traced back to original data; therefore lab notebooks have unique serial numbers, numbered pages, and the pages are not removable. Many laboratories are leaving written lab notebooks behind and are using an electronic laboratory notebook, ELN. ELNs are software programs designed to be searchable and traceable. Many laboratory instruments are now designed to be used with ELN software. ELN software must be designed to maintain the integrity of original data. Safety protocols must be included to protect against manipulation or falsification of original data.
Good laboratory practice is the principles and guidelines for performing laboratory research and recording the research. The Organization for Economic Cooperation and Development, OECD, has developed the GLP guidelines. GLP is used in laboratories which generate data related to the hazards of chemicals in the pharmaceutical, cosmetics, agrochemical, food additives, and other industries where the public comes in contact with chemicals. GLP is also used in many other laboratories to ensure the integrity of the data generated. For more information on GLP see the OECD website.
Image from nih.gov
So obviously your curiosity got the better of you’re reading this blog. You’re probably thinking to yourself, Gowning Benches? I had a contractor call me this week asking a whole bunch of questions. So after doing a crash course, I now know what a gowning bench is made from and used for.
Construction is typically 16-gauge, Type 304 stainless steel for corrosion-resistance and to provide sturdy support for workers dressing for the cleanroom environments. The finishes of the bench vary but the average dimensions are (12″) wide; bench and (18″) high with a rolled rim front and back for worker comfort during changing. Benches can also be adapted for more secure floor mounting or where space is an issue,
there are wall mounted, pull down models, like the one pictured on the left. There are several lengths and widths to choose from, but the common denominator is that all of the above benches that I reviewed strive to meet cleanroom standards.
So you ask, what are cleanroom standards? Before global cleanroom classifications and standards were adopted by the International Standards Organization (ISO), the U.S. General Service Administration’s standards (known as FS209E) were applied virtually worldwide. However, as the need for international standards grew, the ISO established a technical committee and several working groups to delineate its own set of standards.
FS209E contains six classes, while the ISO 14644-1 classification system adds two cleaner standards and one dirtier standard. The “cleanest” cleanroom in FS209E is referred to as Class 1; the “dirtiest” cleanroom is a class 100,000. ISO cleanroom classifications are rated according to how much particulate of specific sizes exist per cubic meter. The cleanest cleanroom is a class 1 and the “dirtiest” a class 9. ISO class 3 is approximately equal to FS209E class 1, while ISO class 8 approximately equals FS209E class 100,000.
By law, Federal Standard 209E can be superseded by new international standards. It is expected that 209E will be used in some industries over the next five years, but that eventually it will be replaced internationally by ISO 14644-1.
As always, our knowledgeable laboratory sales staff here at OpticsPlanet are always available to answer any questions that you have. I do encourage feedback and any suggestions that you may wish to offer. Knowledge is Power!
Electrochemistry is not just pH and conductivity. Currently on the market are Ion Selective Electrodes (ISE) which determine Fluoride, Chloride, Iodide, Sulfide, Cyanide, Ammonia, Nitrate, Sodium, Calcium, Potassium, and other ions. Other common probes are biological oxygen demand (BOD), oxidation reduction potential (ORP), and dissolved oxygen (DO). Electrochemical detectors are being developed which determine organic and bio-molecules in addition to ions. One of the best examples of this is the electrochemical determination of glucose.
Electrochemical biosensors capitalize on the specificity of biological molecules in the sensor for the analyte in question. When the biosensor attached to the working electrode is in the presence of the analyte a catalytic or binding event occurs which results in an electrical signal. The potential of the electrochemical cell is monitored by a transducer and the change in potential is proportional to the concentration of the analyte. One of the advantages of electrochemical determination of molecules is detection levels on the order of picograms, another is fast response time. Combine these advantages with the specificity of biological molecules and you have a powerful detection method. In the future expect new electrochemical products for the detection of biological and organic molecules.
Bacterial cells are surrounded by a cell wall that contains peptidoglycan, which is only found in prokaryotes. Peptidoglycan is a polymer held together by covalent bonds. A molecule made of four amino acids, a tetrapeptide, helps hold peptidoglycan together. Not all bacteria have the same tetrapeptide which accounts for the differences in shape. The cell wall of gram-positive bacteria is composed of 90% peptidoglycan in addition to teichoic acids. Teichoic acids are responsible for the net negative charge on gram positive cells. The cell walls of gram-negative bacteria are composed of a thin layer of peptidoglycan and an outer membrane that encloses the peptidoglycan. The outer membrane forms an additional permeability barrier in these organisms. Humans are born with non-immune factors that protect them from infection from bacteria. Lysozyme is one of these factors and is found in most bodily fluids like tears and saliva. Lysozyme can break down peptidoglycan which results in cell lysis and death.
Well, here’s a nifty item that you don’t see everyday. Dyna-Lume® manufactures a High-Intensity Illuminator in both a dual and single head model (with optional magnifier). Talk about putting some light on the subject! Sorry, bad joke.
This would have been really helpfull to me back in the day when I was soldering circuit boards. It is one of those handy tools that “you need it when you need it”. Available in black and grey, the lamp utilizes a 20W 12V Quartz Halogen Bulbs in Narrow, Combination, or Wide Beam Patterns. The manufacturer boasts that it has a Stepless Electronic Intensity Control, Highly Stable Base, Swivel, Flex Arms and a Solid State Power Supply ( which provides full range electronic intensity control for a precise adjustment of light levels and is calibrated to deliver the highest intensity consistent with long bulb life).
The Micro Quartz Halogen Bulbs: have a Narrow, combination, or wide beam patterns, integral reflector, 3,000 ft. candles at 6″ (3,000°K), 5,000 hour average life, 1.5 in. diameter, double contact bayonet base – (per bulb).
Please note: The Magnifier is an optional accessory. I personally think it should come with. There is also a Micro Heat Shield that is offered as an accessory. I’m sure if you’re using this for long periods of time, the lamp can get quite warm. In review of the specifications, it appears that Dyna-Lume as a well engineered product. One of the things that most impressed me was that it is manufactured right here in the USA. Way to go Dyna-Lume.
As always, our knowledgeable laboratory staff here at OpticsPlanet would be more than happy to assist you with you purchase or to answer any questions that you may have.