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Our website is now mobile friendly! And more...

We have put a new look to our website. Check it out now! Click here and access as a registered customer, with your username and password.
 
There are no major changes to the structure of the website but, there are new features that we feel will make your navigation even easier. 
 
Here are the advantages of our new website, for all our registered customers:
 

 •  Mobile Friendly: Check our ingredients and latest news from your mobile, ipad or tablet. 

•  Save your product research on your “favourites” page and access it later, when you wish, from your PC or mobile.  

•  Easy access from your mobile to our producttechnical and logisticenquiry forms.  

Save articles for later: Have you found an interesting article in our News Alert? Click on it, save it on your “favourites” page and read it later.  

Wittig Reagents

The Wittig reaction was discovered in 1954 by Georg Wittig [for which he was later awarded the Nobel Prize in Chemistry] and involves the use of organophosphorus ylides to produce substituted alkenes. A major advantage of this technique is that the location of the double bond is fixed and a whole range of Wittig reagents [phosphonium or phosphorane compounds] has been developed to capitalise on this.
 
Simple Wittig Reagents are very reactive and unstable in the presence of moisture and air. They are usually prepared fresh in a dry solvent under nitrogen or argon and used immediately. However there are many which are stable enough to be sold commercially, although some have only been developed at R&D scale.
 
Because of its reliability and applicability, the Wittig reaction has become a standard tool for organic chemists in the synthesis of pharmaceuticals, agrochemicals, functional chemicals and their intermediates.
 
From both its global sourcing expertise, and its partner’s production and custom synthesis capabilities, Gee Lawson is able to offer these materials across the spectrum of scale and application. Some examples of the materials available are listed below, but we welcome enquiries for any Wittig reagent from research through to production scale. Please look at our full range of synthetic reagents and ask us for any related item. 
 

Clavulanic acid derivatives – useful β-lactamase inhibitors.

Clavulanic acid is a β-lactam drug that functions as a mechanism-based β-lactamase inhibitor. While not effective by itself as an antibiotic, when combined with penicillin-group antibiotics, it can overcome antibiotic resistance in bacteria that secrete β-lactamase, which otherwise inactivates most penicillins. Its most commonly used form is as the potassium salt [potassium clavulanate], but other salts are also available.
 
Clavulanic acid was discovered around 1974/75 by British scientists working at the drug company Beecham. The name is derived from the Streptomyces clavuligerus, which produces the clavulanic acid. 
 
Clavulanic acid is biosynthetically generated from the amino acid arginine and the sugar glyceraldehyde 3-phosphate.
 
Gee Lawson is able to offer this material in both its Potassium and its Lithium form. For more information on these and other materials in our range please visit our microbiology page or contact us
 

Christmas is here!

Scelto 2

"2015 is fast drawing to a close, and the year ahead opening up in view. To everyone that we have seen, talked to and emailed, and especially our valued customers and partners who make our business a success, we’d like to say a big Thank You. We look forward to building on all those relationships. Have a wonderful Christmas and New Year".

The CLS Team 

Peptide Reagents and Additives

Peptide Synthesis is a major area of activity for modern chemistry and as one might expect there are many synthetic reagents which have been developed to support this. Some were developed many years ago, have been commercialised and find bulk applications. Some are more developmental used in pilot scale production whilst others are still more research related.

The major coupling reagents themselves fall into three categories: Carbodiimides, Phosphonium and Uronium based chemicals although there are other more individual reagents which find important uses, such as EEDQ.

 

Carbodiimides include the classical DCC, and the slightly more easy to handle DIC which is particularly useful for automated SPPS. EDAC HCl was particularly designed as a reagent for aqueous solution couplings. All these materials are available for commercial applications.

 

Phosphonium-based coupling reagents do not affect amino groups and with some limitations are well suited to be used as cyclization reagents. They include (Benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate

 

Uronium reagents include TBTU and HCTU, each providing special areas of strength in application.

 

Peptide coupling reactions also employ various additives which enhance the process in various ways and these include HOBt, HOSu and DMAP.

 

Gee Lawson is able to offer all the materials mentioned above, and welcomes enquiries for other novel peptide reagents or relevant additives.

Product highlight: Leishman stain

Leishman stain (CAS: 12627-53-1), is one of the Romanowsky stains [which also includes Giemsa, Jenner’s and Wright’s Stains]. It is used in microscopy for staining blood smears, for example where it is generally used to differentiate and identify leucocytes, malaria parasites, and trypanosomas. It is considered to provide excellent staining properties. The technique is relatively easy and so is often used where results are required quickly or where the routine laboratory method is not available [eg at night].

 

Leishman Stain is applied in conventional staining techniques to uniformly stain chromosomes. These techniques leave centromers constricted, thus enabling the measurement of chromosome length, centromeric position, and arm ratio. Slides can be easily de-stained and banded by most banding procedures. It reveals cytoplasmic details and granules well and is a favoured technique of haematologists.

 

The diagnosis of malaria involves the identification of the malaria parasite or its antigens/products in the blood of the patient. Microscopic tests involve staining and direct visualization of the parasite under the microscope. For many years the direct microscopic visualization of the parasite on the thick and/or thin blood smears has been the accepted method for the diagnosis of malaria in most settings; from the clinical laboratory to field surveys. The careful examination of a well-prepared and well-stained blood film currently remains the "gold standard" for malaria diagnosis.

 

Although the classical uses are widespread, Leishman can be used in other less obvious diagnostic investigations; for example the examination of facial ulcers.

 

Gee Lawson supplies an excellent quality of Leishman Stain. Visit our dedicated product page. Remember to login as a registered user, if you wish to download techincal information directly from our website.

Please ask us about your requirements for this product, or for any specialist dye and stain materials (click here to see our product range).

LEHVOSS acquires UK-based Gee Lawson

Hamburg, August 2015

LEHVOSS UK Limited, the UK subsidiary of Lehmann&Voss&Co., Hamburg founded in 1894, is pleased to announce the successful acquisition of Gee Lawson Holdings Limited. This acquisition is a strategic move that strengthens the LEHVOSS Groups portfolio in the nutritional and life science sectors across Europe and globally.

Read more >

New Monomers for High Performance Polymers, including applications in 3-D printing.

Conventional manufacturing methods for aircraft metal parts tend to be inefficient and wasteful. Producing a 1-kilogram bracket for an airplane, for example, may require 10 kilograms of raw material and that final bracket may still contain more metal than is required. The same principle applies to other high-technology industries.

 

3-D printing requires less raw material input and can produce parts that minimise weight through better design. However, to really develop this potential, scientists need to improve the technology since issues such as surface quality, repeatability and throughput are current barriers to full-scale production. Click here to read more.

 

3-D technology is also developing in aerospace and other high technology areas, such as medical devices, using new polymer materials. These new materials have special fabrication properties and involve the detailed investigation and commercial production of difficult to synthesise monomers.

 

In addition to slightly more classical monomers such as 4,4’-Diphenoxybenzophenone, for example, Gee Lawson has direct access to a production partner who has developed a new range of speciality monomers which can be used in the production of high performance polymers. Some of these products can be found on our website, including, for example, 1,3-Phenylenebis(4-hydroxyphenyl)methanone [CAS 5436-05-5], and 5,5’-Oxybis[2-(4-phenoxyphenyl)-1H-isoindole-1,3-dione [CAS 34335-81-4].

 

We welcome any enquiries for these materials, or for custom synthesis requirements for other speciality monomers. 

OPA [ o-Phthaldialdehyde]: Versatile Organic Reagent

OPA   [ CAS 643-79-8 ]  is an organic di-aldehyde which is useful in the synthesis of heterocyclic compounds, but which finds a number of important applications.

In the research and diagnostic area OPA is used in a very sensitive fluorescent reagent for assaying amines and sulphydryls in solution; for example in proteins, peptides, and amino acids. In winemaking it is used in the testing of yeast assimilable nitrogen [YAN] which is measured not only as an indicator of quality but also the progress of the fermentation process.

OPA finds applications in polymers where, for example, end-capped poly(phthalaldehyde)  [PPA] is a well-studied metastable product. Applications include photoresists.

It is also commonly used as a high-level disinfectant for medical instruments, where it sometimes replaces the traditional use of glutaraldehyde. Applications include disinfection for semi-critical instruments that come into contact with mucous membranes or broken skin, such as specula, laryngeal mirrors, and internal ultrasound probes.

 

As one of just many speciality chemical products, Gee Lawson can supply both high-quality OPA for diagnostic applications and more commercial material for larger scale use. Contact us to find out more. 

Impact of Explosion at Tianjin, China

You will have seen the reports of the major explosion at Tianjin. This serious incident has had knock-on effects on the shipping of goods from China. Tianjin is now generally operational, although there may be delays due to shortages of containers and equipment.

The major issues are around dangerous goods, with the government imposing more rigorous checks on this type of cargo. This is also spilling out to other ports where, for example, goods at Qingdao and Shanghai port are now also subject to more controls. We are also seeing signs of more restrictions on hazardous shipments at airports, even for samples. Some indications are that this situation may continue until mid-September but it is too early to be sure if that information is factual.

Please be assured that Gee Lawson is working with its suppliers and global logistics partners to minimize the impact on business, but it does seem clear that there will be delays in hazardous chemicals leaving China in the coming weeks. 

If you have any specific questions, or if you are having problems obtaining materials through your normal sources, please do not hesitate to contact us.