Monthly Archives: June 2014

Sterlitech's offices will be closed on Friday, July 4, in observance of Independence Day. We'll be back on Monday, July 7 to help you find the best solution to your laboratory filtration questions.

Defining a Pore Size and Sterile Filtering; 0.2 Micron vs. 0.22 Micron.  What’s the difference?

If you were to spend a little time perusing Sterlitech’s selection of membrane disc filters, one thing we’re very proud of might just jump out at you: we have a lot of pore sizes. So many that you might wonder if it’s a little excessive that we carry both 0.2 and 0.22 micron pore sizes. After all, both are used to sterilize fluid passed through them. Can the tiny difference of 0.02 microns really change a filter’s performance characteristics that much?

To answer that question, we must first take a look at one of the methods used to test a filter’s performance: the bubble point test1. Standard tests to verify a filter’s stated pore size usually entail a bubble point test. This test pushes air under pressure through a submerged membrane (either in water or alcohol) to the point where air bubbles first begin to come through the filter membrane2. The largest pore, or pores, in the membrane will

Since 2007, the Southern California Coastal Water Research Project has been monitoring the impact of fecal indicator bacteria (FIB) on public health at Doheny, Avalon, and Surfrider beaches in California (just when thought it doesn't get worse than peeing in the pool).  They explain and summarize their tracking efforts in a neat video below.   Sterlitech also offers analytical funnels, Grade F glass fiber filters, manifolds, and microbiological monitors that are similar to the ones you see in the video.  If you are also working with or involved in microbiological monitoring, we are also developing a new microbiological monitor that uses a polycarbonate membrane filter in place of the usual MCE filter.  You can contact us here, if you would like to learn more.

Sterlitech Corporation is adding the EZWaste Safety Vented Carboy to its roster of ergonomic, compact fluid storage and transport equipment. These new, specially vented carboys are designed to help scientists create a safer laboratory environment by reducing the risks of spills and preventing hazardous solvent vapors from infiltrating the lab. The EZWaste Safety Vented Carboys are a direct descendent of the EZGrip Carboys currently offered by Sterlitech, which means they share the same efficient, ergonomic design. What sets the EZWaste apart from the normal carboy is a special VersaCap with integrated tubing connections and an activated carbon exhaust filter. Each EZWaste system comes with extra plugs for any unused ports in the cap, and a sulfur-cured EPDM gasket to ensure a tight, chemically resistant seal. Once waste collection is complete, the vented cap is easily replaced with a standard cap for storage or transport to a designated waste facility. “Many organic solvents common to

Sterlitech Corporation is adding new product options to its line of silt density index (SDI) testing devices. Sterlitech is offering these all-in-one units in response to the industry’s demand for a convenient and durable on-site tool for measuring the fouling capacity of the feed water used in reverse osmosis systems. Silt density index testing quantifies the amount of particulate contamination in a water source and is used to estimate the rate at which membrane fouling will occur, particularly in applications employing reverse osmosis membranes. The SDI of a feed source is measured by running a stream of feed water through a 0.45 micron filter at a constant pressure and calculating the rate at which the flow slows down (ASTM Test Method 4189-07). “Accurate and reliable SDI testing is key to maintaining good efficiency in membrane purification facilities and to help keep operating costs down, especially when dealing with sources like seawater which have a highly variable SDI,” notes