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. (more…)
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 the insect cells, which in this case were Sf9. (more…)
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 microbial visitors! (more…)
For a follow up to our last blog we want to talk about maintaining healthy cells over the holiday period spanning Christmas and New Year. Ok, if you are like our CEO you don’t really want to be thinking about the office Christmas party so early, but end of year is creeping up on us. Most labs, academic and industry, will have some time off. It is often a problem keeping your cell cultures in good condition so that when you return in 2017 you can pick up that important protein expression project without too much delay. Given that most insect cell lines (usually Spodoptera frugiperda or Trichoplusia ni cell lines) need to be sub cultured at least twice a week if they are grown as suspension/shake cultures, how will they survive for this protracted period? (more…)
Following on from our last blog on the revival of cells stored in liquid nitrogen, we now provide some tips on the continued healthy culture of insect cells. Whether you are maintaining cells as monolayer or suspension (shake or spinner) culture you will probably faithfully record your name/medium used/date of sub culture/passage number on the side of your new flask. Alternatively, instead of using a new flask you may simply dilute the cells in their existing vessel and continue to culture them – more about this below. A question that often vexes people is how many times a culture of cells should be sub cultured or passaged before they are no longer fit to use. There is no simple answer to this question as it relates to the healthy culture of insect cells. (more…)
Hopefully after the seasonal break your insect cells are still in good health. Recognizing healthy cells seems a no brainer, but if you haven’t got much experience with insect cells it can be more of a problem. Experts often talk about “shiny appearances” and “well defined membranes”, which is fine if you know what they mean but puzzling if you are in your first foray into cell culture. So to help you out, in this blog we provide some images of Sf9 cells in various conditions. We set up a small shake culture and then sampled cells over the next few days by observing them after decanting 1ml into a 35mm culture dish. We used a microscope set up for bright field vision rather than phase contrast. The latter has its uses but for this purpose ordinary light seems to work best. (more…)
So, you have had the Christmas Party and hopefully are looking forward to the holiday season. Many labs shut down between Christmas and New Year and you may not return until January 4th. In all the build up to the festive season have you remembered everything? Aunt Hilda’s bottle of lavender water and Uncle Horace’s box of cigars may be already wrapped and under the tree but aren’t you forgetting something? What about the insect cell cultures that you tend carefully the rest of the year but are now possibly going to neglect for the next 11 days? Most insect cell lines (usually Spodoptera frugiperda or Trichoplusia ni cell lines) need to be sub cultured at least twice a week if they are grown as suspension/shake cultures. How will they survive for this protracted period? (more…)
No, not how you feel when the cells don’t behave! This relates to keeping your cell cultures in a happy state.
1. Cell passage history
Each time you sub culture your cells you probably faithfully record on the new flask various bits of information such as the name of the cell line, date, the medium used and passage number. This last item ideally relates to the number of times the cells have been sub cultured since they were first isolated. However, it is unlikely that this is the case for many cell lines.Passage histories may become lost over the years and often this number simply refers to the first time the cells were cultured in your own laboratory. (more…)
Cell culture may be one of the most routine laboratory tasks, but many times it also proves to be extremely frustrating.
Cells grown in the labs are living organisms, and they seem to have the mindset of a moody teenager – happy one moment and extremely upset the very next one. Unfortunately (or fortunately) unlike teenagers they are not able to throw a tantrum and scream out what bothers them. Instead, they resort to sulking behaviour – change appearance, refuse to grow and eventually die. (more…)