Wet Lab best practices and rules

General Principles

Don't leave problems for other people. If you identify a problem, immediately report it to the tech team, Simon, or the group Whatsapp as appropriate. Do not leave it for the next person to solve. For example if a hood doesn't have a pipette in it, grabbing a pipette from the next hood is not appropriate, unless you tell the tech team you've done that so they can find the missing pipettes.

Leave things as you found them. This includes putting things you borrow back where you found them when you're finished, nothing is worse than someone moving something. Remember if you move something to a different shelf/fridge/cupboard you'll need to update LabSpend so that everyone knows where they can find it

Sharing by default. Sharing reagents saves us money and lets us do more science. If someone asks to borrow/use something that you ordered, your default answer should be yes. We often don't know if sharing something is a problem until we check shipping times to replace the borrowed item. So the best place to ask to borrow something is the #wetLab Slack channel. This lets Simon prioritise the needs of multiple projects appropriately while checking any delays it might cause. If someone asks to borrow/use a reagent "let me check with Simon", or "can you ask in Slack" is a good reply. Don't just say no. Instead pop it in Slack and let Simon say no for you.

Don't take anything without asking. It doesn't matter if you think someone isn't using something, you should always ask before taking something. If it's a last minute request that needs an immediate answer for an in progress experiment, please still pop it in the #wetlab Slack channel and Simon will approve.

Everything belongs to the lab. While it's important to be able to reserve things for your upcoming experiments (on LabSpend), everything ultimately belongs to the lab. Items ordered for one project may end up being best used in another project, or even gifted to other labs. Simon will make these decisions with the goal of keeping grants coming into the lab to keep the science flowing.

Mycoplasma

We have an Red/Amber/Green incuabtor system to ensure mycoplasma negativity

• Red = Primary samples which can never be free from mycoplasma

• Amber = Untested, freshly aquired cells which may or may not have mycoplasma

• Green = Tested cells that are definitely mycoplasma free

When you get new cells up you should mycoplasma test them as soon as possible. If you are mycoplasma testing your cells you should offer (in the group Whatsapp) to test other people's cells if you have any free lanes in your test. Once tested you must move your cells to the green incubator. The Amber incubator must not be used for long term culturing.

Cell Line Validation

All cell lines we aquire from other labs, or that haven't been Short Tandem Repeat (STR) tested before, must be STR tested. We order cell line authentication barcode from Eurofins for this purpose. If we are out please place an order for some.

Cell lines purchased from reputable sellers such as DSMZ/ATCC arealready validated and do not need str testing.

What to do when you first aquire a new cell line

It is essential that when you first aquire a cell line you must build up a gold standard master bank of validated, low passage cells. You must:

• First put the cells in a T75 flask, when this flask is confluent, freeze down 1-2 vials (depending on cell number).

  • Put these p0 vials in a communal freezer box.

  • Mycoplasma test these cells as soon as possible.

• Divide the remaining cells over 2-3 T75 flasks. When each flask reaches confluence, freeze down 3-4 vials and seed 1 new T75 flask, keeping the old T75 flask, wherein some cells are left that also keep growing. In this way you will soon have 20-30 vials frozen down with <p5.

  • While bulking up cells in this way send a cell pellete to Eurofins for validation if the cells were not obtained from DSMZ/ATCC