How do you take your cephalexin? Half as frequently, if you use a new formulation.

Anything that helps patients follow their treatment regimen is good.  One common example is the idea of reducing the number of pills that a patient needs to take.  That is, rather than giving a small dose at 4 hour intervals, you give a larger dose at 8 hour intervals.  That doesn’t work, though, if the body takes that larger dose and releases it into the system immediately; so the trick is to develop extended release formulations.  That’s what a research team led by the Department of Pharmaceutics at the School of Pharmacy of Suresh Gyan Vihar University in Jaipur, India did with cephalexin.  Of course, any time a new drug formulation is made, it’s stability has to be evaluated, and the stability chamber is the tool for the job.

Amphibian defensive skin secretions have antimicrobial properties that could benefit human health.

It’s much harder to measure anything when the measurement destroys your sample.  If your sample is a living organism, then it’s even more difficult: you have to maintain lots of organisms and then extrapolate the condition of one sacrificed animal to another sacrificed at a different time.  It’s even worse when your sample animal is part of an endangered taxon.  That’s the situation with amphibians, but they’re so worth studying that a joint Irish and Chinese research team developed a method to analyze skin secretions containing mRNA from these amphibians, obviating the prior necessity to sacrifice them to analyze the secretions.  Even better, the samples stay stable in the laboratory freezer for as long as six years.

Even if it is just an exercise, temperatures about 100 degrees F would be enough to induce thoughts of going AWOL.

Just in case you were lacking reasons, here’s one more reason to admire people who serve in the military.  This 1994 report from the U.S. Army Research Institute of Environmental Medicine summarizes the experience of an army brigade during a three week simulated battle training exercise.  Specifically, the report examines heat stress suffered by the soldiers during a time when the noontime temperature averaged 104 degrees F (about 42 degrees C).  Soldiers who presented with heat-related symptoms were given IV liquids cooled in a blood bank refrigerator.  Then, in the middle of the three-week exercise, the refrigerator stopped working and they were given IV fluids at temperatures up to 106 degrees F. Doesn’t sound ideal to me.

Vaccine preparation tools have come a long way, but the laboratory incubator remains an essential lab apparatus.

Some laboratory instruments are almost timeless. Sure, technology advances, but the basic role of the instruments are so essential to laboratory operations that older versions are simply replaced with newer.  The analytical balance is one such instrument, and the laboratory incubator is another.  This 1952 paper outlines work done by researchers at the Department of Bacteriology and Immunology at the Jefferson Medical College of Philadelphia to stabilize the lyophilized BCG vaccine—the tuberculosis vaccine.  The paper compared the stability of various formulations stored at lab refrigerator temperatures and in a 38 degree C incubator.

Here’s a cute little video illustrating the measurement of percent water in a hydrate. Actually the video isn’t that cute, but the music is. And I find it kind of irritating when someone uses “mass” as a verb, presumably in some attempt to clarify the difference between mass and weight, but really, can’t you just “weigh” the crucible? Because that’s what happens here: a crucible is cleaned, dried, and weighed on a scientific digital scale. A hydrate is added and the sample reweighed. The sample’s heated and the water’s driven off and the sample is reweighed again.

Florida students examined red mangrove seedlings to determine their adaptation to dark and light environments.

Everybody knows leaves thrive in the light and starve in darkness.  But a good percentage of science is examining things “everybody knows.”  That’s at least part of the lesson learned by this group of Florida students who examined the difference between leaves raised in the sunshine and in the shade.  They collected a number of leaves from mangrove seedlings found in sunny or shady environments and stored them in a laboratory refrigerator prior to analysis.  That analysis included quantifying the stomata, the transpiration rate, the leaf succulence, and the chlorophyll content.  Their experiments “pointed to shade seedling adaptations to cope with the extra stress.”

Norfolk Harbor is one of the three locations where the U.S. Navy used antifouling paint that can be an environmental contaminant.

Once there was an undersea king whose daughter was sick.  A grizzled little man promised to heal the daughter if the king would give her to him—unless the king could guess his name.  Sam?  No. Jubalnox?  No.  Tributyltin?  Yes!!! And the princess lived happily ever after in her undersea castle.  Well, that COULD have been the story of tributyltin.  Instead it’s a contaminant derived from the U.S. Navy’s antifouling paint, and the EPA wants it monitored.  This 1989 report outlines how it’s done, including sampling the waters of Norfolk harbor with polycarbonate bottles that were stored in the laboratory freezer until ready for analysis.

Nor-Lake Select 24 cubic foot pharmacy refrigerator

The value of laboratory samples and pharmaceuticals stored in lab refrigerators can be substantial, which is why laboratory refrigerator temperature control should figure prominently when purchasing such units. 

Several types of temperature control mechanisms are available on lab refrigerators, the most basic being dial-type thermostats without temperature indications.  They simply allow you to select “on, normal, and cold,” or provide number settings such as from 1 to 7 but with no indication of what they mean in terms of temperature. While these basic units are relatively low in cost they are not the wise choice when content value is high. 

Top-of-the-line laboratory and pharmaceutical refrigerators such as the Nor-Lake Select glass door series available from Tovatech have highly sophisticated PLC (programmable logic controller) temperature control technology for situations where absolute minimum temperature drift is essential.   These units allow scientists to set temperatures to one decimal place. Temperature drift and uniformity data are available for the four Norlake Select models.  An empty 24 cubic foot unit, for example, showed a drift of ±0.15⁰F when the unit was set at 40.0⁰F.  Norlake Select lab refrigerators filled with product exhibit less drift. A password is required in order change set points.

Monitoring and Alarming Systems on Pharmacy Refrigerators

While continuous product temperature display is available on several Norlake Scientific refrigerators the Select series has three temperature sensors, two for products in storage and one for the internal air.  These are positioned in the cabinet to support validation of internal temperature uniformity.

A multi-level alarming system provides enhanced product safety. Components include:

• Audio and visual high-low temperature alarms alert in the event of temperature excursions
• Remote alarm contacts send alerts to locations elsewhere in the laboratory  
• Sensor failure alarm
• Audible and visual door ajar alarm

Alarm volume as well as beep or constant can be selected, and the back-up battery power has a low-battery test switch.

Other monitors built into the auto-defrost Select series glass door lab refrigerators report on the number of door openings (with a 24-hour reset), and the fan motor, defrost heater, condenser and compressor run times.

The enhanced temperature control, monitoring and alarming features set the Nor-Lake Select series of lab refrigerators apart from the Premier line.

Four Select Laboratory Refrigerator Sizes

The Select lab refrigerators are offered in capacities of 24, 33, 52 (2-door) and 80 (3-door) cubic feet.  Three coated wire shelves are provided per door.  All models have a real time clock/date display, switch-activated interior lights and are equipped with a 1-inch diameter sensor access port.  The lockable full-size double-pane glass doors have pull handles and magnetic gaskets. 

Options include extra shelves, stainless or wire basket drawers, stainless interiors and exteriors, an internal electrical outlet, a 2-inch access port, temperature chart recorders, additional data ports and enhanced locking security.

Contact the scientists at Tovatech for additional details on these high-end Select laboratory refrigerators or for professional advice on specifying laboratory refrigerators and freezers.

Frost can damage plant crops, so understanding how plants freeze can be the first step in preventing some of that damage.

Normally a laboratory incubator is used to create conditions just right for growth of a culture, say 37 degrees C.  Of course, incubators are flexible enough to accommodate other desired growth conditions, but it’s not too often that one is used to attempt to freeze living cells.  That’s just the case in this 1985 Plant Physiology paper from researchers at the Agricultural Research Service of the USDA. They were attempting to understand the mechanisms of ice nucleation in plant material. They found it to be a complex problem.  To wit: “The number of factors influencing ice nucleation temperature suggested that predicting the freezing behavior of plants in the field will be complex.”

Why does blood go bad in the refrigerator?

We know that units of extracted blood last about six weeks in the blood bank refrigerator, but why? What are the mechanisms of its degradation?  If you want to know, you aren’t alone, because researchers from the Mayo Clinic and the University of Minnesota had the same question. They reported on their research in a recent paper. They correlated spectroscopic measurements with “metabolic changes, RBC morphology, cholesterol and membrane protein loss, phospholipid reorganisation of the RBC membrane, and peroxidation of membrane lipid.” They found that much of the change was almost immediate upon storage.