Resources

Expression Systems insect cell culture media

OET is pleased to offer a wide range of Expression Systems Insect cell culture media, from the very popular ESF 921, to specialized insect transfection media. Expression Systems’ media are easy to adapt your cells into and the insect specific media gives great protein yield, when compared to rival media.   ESF921 insect culture media OET use ESF 921 for all in-house work, due to it’s high performance record, whilst

Adapting insect cells to a new growth medium?

Have you ever had the experience of adapting insect cells to a new growth medium?  We recently had to do this for a client project because they had used a particular medium previously and were keen to maintain the same conditions to continue the work with us. This process made us realise that switching to a new serum-free insect cell culture medium can result in short term stress responses in

Baculovirus-expressed secreted recombinant proteins

A question that often comes up from clients is what is the best signal peptide to use for baculovirus-expressed secreted recombinant proteins?  While we have discussed the best flashBAC™ variant to use for the production of secreted proteins in a previous blog, we have never considered the role of the signal peptide. In fact, while writing this blog, we realised that there was much that we didn’t know, so will

baculoQUANT titration of recombinant baculoviruses

There are many methods available for the titration of recombinant baculoviruses.  One of the most convenient is the use of the quantitative polymerase chain reaction (QPCR), which assesses how much virus DNA is present in a freshly-amplified stock.  This is compared with a standard curve derived from a control virus stock to give an infectious titre expressed as Q plaque forming units (pfu) per millilitre.  OET Ltd market the baculoQUANT™

Sequence errors in your gene for expression Part II?

Sequence errors in your gene for expression Part II follows on from an earlier blog where we discussed a problem we were having producing a particular protein after synthesizing a gene based on very old sequence data. The baculovirus we made containing this synthetic gene produced very low levels of recombinant protein that were hardly visible after immunoblot analysis. This wasn’t a good start to a project where a purified

Sequence errors in your gene for expression? (Parts 1 + II)

If you don’t achieve the levels of protein expression expected in your project, have you ever considered that there may be sequence errors in your gene?  This applies to all expression systems, not just those based on baculoviruses.  We should be clear that we are not talking about sequence errors in your gene after it has been synthesized by an out sourcing company.  Quality control by such companies is such

flashBAC 5+1 offer

OET’s flashBAC 5 reaction kit ranges are some of our most popular products. However, recent feedback has revealed that some customers are reluctant to make use of the positive control transfer vector as this sacrifices 1 reaction and so reduces the number of their own viruses that they can produce. In recognition of this issue, until further notice, we are increasing the amount of flashBAC DNA in all of our

Quick guide to plaque assays

Quick guide to plaque assays of baculovirus infectivity.  Last week we ran a short training course on baculovirus expression vectors.  As part of this we put together a one page guide for carrying out plaque assays.  This might be useful to those of you looking for something you can have on the lab bench while conducting your own plaque assays.  We have added a image of one of our 12-well

Transduction of whole porcine kidneys with BacMams

One of the unexpected offshoots of the baculovirus expression system has been its development as a vehicle for the delivery of genes to mammalian cells.  These vectors are otherwise known as BacMams.  Although baculoviruses are unable to replicate in mammalian cells, they can enter them via receptor-mediated endocytosis.  In Frederick Boyce’s original paper the Rous sarcoma virus promoter was used to express beta-galactosidase in the HepG2 human liver cell line. 

QPCR baculovirus titration

QPCR baculovirus titration avoids: – plaque assays – ELISA or immuno assays – virus extraction spin columns KEY FEATURES – baculoQUANT all-in-one • Titre accuracy comparable to plaque assay method • Less than one hour hands-on time • Compatible with any AcMNPV-based baculovirus system containing gp64 virus gene • Single step virus DNA extraction: just add lysis solution (no spin columns) • QPCR Primers/Probe provided as a single reagent mix:

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