News Stories

When to Passage Sf9 Cells

An important factor in baculovirus expression is assessing when to passage Sf9 cells, which are commonly used to make recombinant viruses or for protein production.  In our last blog we talked about how to make the transition from monolayer to suspension cultures and how maintain cells in a healthy state during this time. To define what is meant by ‘healthy’ cells,  Figure 1 shows a sample of healthy Sf9 cells

Suspension Sf9 Cells from Monolayer Cultures

The transition to suspension Sf9 cells from monolayer cultures is not difficult but does depend on harvesting the attached cells at the right time. Too early and it is extremely hard to detach the cells from the culture flask. Too late and the cells will be in such poor condition that they may not recover when in suspension. Trying to describe in words how the monolayer culture should look prior

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™

Reviving Cells from Liquid Nitrogen

The process of reviving cells from liquid nitrogen, or indeed from transport on dry ice, can be a little difficult on occasion.  Two events at OET recently have highlighted this. Firstly, we received a new cell line that came with a very complicated procedure for its culture – it is a mammalian species, quite different from your run of the mill HeLa’s and HEK293’s.  Its culture is known to be

Co-infection with Baculovirus Vectors for Multiple Protein Expression

A question that comes up from time to time is the use of co-infection with baculovirus vectors for multiple protein expression in insect cells.  The need arises if you have produced a number of baculovirus vectors that each synthesise a component of a multi-subunit complex, such as an enzyme or a virus like particle.  Intuitively, you know that it is probably necessary to add many virus particles per cell to

Baculovirus Transfer Vectors Compatible with flashBAC™

A question we are asked from time to time is to identify baculovirus transfer vectors compatible with our flashBAC™ system. We obviously nominate our own extensive range that is available but frequently someone has an old plasmid from years ago that they want to reuse. Originally they may have paired it with a linear DNA system such as BaculoGOLD or BacPAK6 or even wild type DNA where recombinant virus selection

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

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

OET at ISBioTech Washington 6-8th March

OET founders, Linda King and Bob Possee will be attending ISBioTech in Washington, 6-8th March 2017.  Linda will be presenting a talk entitled, “BacMam Expression Vectors: Applications in Gene Therapy”.  The use of BacMAMs for recombinant gene expression in mammalian is an ever expanding application of baculovirus vectors.  Her talk will encompass some of her research group’s recent work on the potential use of BacMams to transduce whole organs and

Sf9 cells from monolayers to suspension cultures

Transferring Sf9 cells from monolayers to suspension cultures can sometimes be difficult.  These insect cells, commonly employed for baculovirus-mediated expression, are usually kept growing in suspension culture.  However, sometimes monolayer cultures are used to keep them going during periods of low demand.  These cultures are also useful as a reserve or back up for the main suspension cultures, which even in the best laboratories can sometimes become contaminated with unwanted

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. 

OET is now https://

We recently updated our web site to https:, which is apparently a jolly good thing!  (Although our CEO is still struggling to understand it all).  This shouldn’t cause any problems for users of the site, but if you have any issues such as problems logging into your account then please email us at and we will help you out.

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