Product Quality Discussion
Product identity and purity are important! At LC Laboratories we take great care to provide products of the highest purity and activity.
Low price does not mean low purity. LC Laboratories' prices are often 30-80% lower than those charged by other suppliers, especially for the most widely used products such as kinase and phosphatase inhibitors and activators. However, our lower prices do not signify that our product purities are lower as well. Quite the opposite: we believe that the purity of each of our products is equal to, and in most cases greater than, the purity obtainable from any other source worldwide.
Our manufacturing advantages. While it may be a little difficult to see how that is possible — higher purity for a lower cost — the reason is simple. We manufacture or thoroughly analyze all of our products ourselves, and we have large-scale preparative liquid chromatography purification capabilities. Over the past 36 years we have developed numerous proprietary, very efficient, low-cost production methods that have been optimized to provide very high final purity. We have also located very low-cost sources of raw materials for our manufacturing.
No middlemen for manufactured products. When you purchase directly from LC Laboratories, there is no additional cost for a middleman. When middlemen such as our larger competitors buy and resell products, usually that introduces a two- to ten-fold increase in the product cost.
Intense focus on purity. We also take extraordinary care to study and verify the purity and stability of our products. This is extremely important, because many popular products have subtle purity or stability problems that other vendors often ignore. Examples include okadaic acid products, calyculin A, chelerythrine, phorbol esters, and bafilomycin A1. (More information about these products and the special problems associated with them is presented below.)
Small number of products means more attention to each product. LC Laboratories currently offers only about 174 products. Thus, we are able to pay a lot more attention to each product's production and final purity than companies offering thousands of products. To be more specific, we sell (on average) a lot more of each of our products, particularly in terms of milligrams or grams, than do other companies having thousands of products. So, we can spend more time per compound being sure that the purity is what it should be.
Also, our prices are low because:
- we don't rent expensive booths at trade shows
- we don't publish massive catalogs in expensive rainbow colors
- we don't place full page, full color ads in journals such as Science and Nature
- we don't spend our (your) money on "free" mugs or T-shirts
MORE ABOUT PURITY
We are aware of many instances where unrecognized purity problems have led to large amounts of research work being compromised or even rendered useless due to spurious results from substandard reagents.
Here are some examples of product purity or activity problems in the signal transduction reagents business:
Some years ago a major vendor supplied the wrong isomer of the kinase inhibitor H7 to numerous laboratories; the wrong isomer had substantially different biological properties and results obtained with it were incorrect. Scientists in our parent organization detected the problem and published correcting data in conjunction with a collaborating academic laboratory [Biochem. Biophys. Res. Comm. 187: 657-663 (1993)].
Okadaic Acid products suffer a considerable stability problem. Although reasonably stable in bulk form, okadaic acid can degrade immediately by as much as 40% or more when subdivided into sub-milligram quantities and vacuum-dried for final sale. Many vendors do not properly test the final products after packaging, and our analyses show that several other vendors' okadaic acid is less than 60% pure in some cases. We have been repeatedly told by our customers that our okadaic acid is more active than material obtained from other suppliers.
Chelerythrine Chloride is the subject of considerable turmoil because of some poorly understood problems.
First, for many years we have noted that some other sources of chelerythrine are contaminated with significant amounts of biologically active impurities, such as sanguinarine, which are very difficult to remove from chelerythrine purified from its natural source. In contrast, our chelerythrine is made by a rigorous, multistep process that includes HPLC and crystallization steps, and the resulting purity is extremely high and reproducible.
Second, we have been informed by researchers that other vendors' chelerythrine shows variations in biological activities from lot to lot.
Third, it is suggested in some publications that chelerythrine does not show the potent PKC inhibitory activity that was initially ascribed to it in 1991 [Biochem. Biophys. Res. Comm. 172: 993-999 (1991)]. This 1991 report used chelerythrine isolated from a natural source, and it may have been contaminated with an interfering compound that inhibits PKC catalytic activity. Other, more complicated explanations may not be ruled out, however.
It is nonetheless quite clear that chelerythrine potently blocks many effects of PKC activators such as phorbol esters, but it is possible that these effects result from an interaction with PKC that does not involve actual kinase activity inhibition per se.
Rottlerin was reported in 1994 to be a somewhat selective inhibitor of PKCδ, but a more recent study has failed to show any PKC inhibitory activity at similar concentrations. The 1994 study used rottlerin from a source whose material has consistently proved to contain substantial amounts of impurities when we analyzed several lots. The subsequent failure of a very competent laboratory to reproduce the original rottlerin results, along with other considerations, compelled us to discontinue this product. More information can be found on our rotterlin product page by clicking here.
We have been informed by researchers from three different, unaffiliated academic laboratories that our PMA performed better in various biological systems than material obtained from other sources.
Purity and Price Are Not Correlated!
The prices charged by biomedical reagent vendors for a given product tell you
nothing about the purity.
For example, as shown in our Purity/Price Comparison Table for Rapamycin you
- $182 to Abcam for 1 mg of 98% pure rapamycin
- $245 to R&D Systems for 1 mg of 98% pure rapamycin
- $252 to Sigma for 1 mg of 95% pure rapamycin
- $438 to Calbiochem (EMD) for 10 mg of 99% pure rapamycin
- $53 to LC Labs for 50 mg of >99% pure rapamycin!
Another example is cyclopamine:
- Among the many other cyclopamine suppliers, 19 suppliers charge $18 to $194 for 1 mg;
only 3 suppliers claim >99% purity; 12 claim only 98%; and another 4 claim only 97%.
- LC Labs' price for 25 mg of >99% pure cyclopamine is $84—$3.36 per mg—1/5 to 1/64 of the cost from the suppliers noted above.
The picture is clear -- price tells you nothing about quality.