Pipetting with precision - how to minimise experimental error

[@salah-dred8576]

This content is what a biologist need, practical, clear and right to the point. Thank you my friend !

[@BioLabCollective]

Thank you for the feedback!

[@Eve.Daniels]

OMG where was this video two years ago 🥲 I learned to pipette from diagrams in old textbooks during lockdown. Didn't even THINK to look on KZbin until a year later 😭

[@BioLabCollective]

Glad you found the channel!

[@Weatherman4Eva]

Thank you very much for this! I'm applying for a job as a biochemistry lab assistant and it's been quite a few years since college so I'm brushing back up on the fundamentals

[@BioLabCollective]

Glad it helps - good luck with the job hunt!

[@chubbyobasi814]

Thank you for this video. I really appreciate your honesty. As simple as it my seem, the errors from pipetting are shocking. One thing to add tho when dispelling, after the first stop an angle should be made to at least touch the side of the tube before pushing to the second stop(blow off). Helps in accuracy involving smaller volumes. Thanks again❤

[@BioLabCollective]

Glad it was helpful!

[@theelusivememe1772]

Okay so the first stop is for drawing up liquid and you only go to the second stop when dispensing. But am i suppose to press the second stop while submerged in the liquid cause i always get bubbles, or do you only press to the second stop unsubmerged in the liquid?

[@BioLabCollective]

Generally we don’t dispense liquid with the pipette submerged in liquid? Pipette to the side or the opening of the tube and bottle to minimise disruptions on the liquid you are pipetting into

[@kiklly]

Thank you so much for this video.

[@BioLabCollective]

Glad to hear it’s helpful!

[@ervincui1914]

When I am depressing the pipette, I go to the first stop and then the second stop and pull away fast to avoid any little bit of liquid adhereing to the inside of the tip. However, there’s always a little bit left and when I aspirate again it is visibly more than the first time I aspirate with a new tip. How do I make sure I’m pipetting all of the volume out consistently?

[@BioLabCollective]

Sounds like you are pressing too hard (slightly past the first stop) when drawing up liquid, hence the additional air or liquid in your pipette. Could also be the consistency of the speed at which you press the plunger - needs to be slow and smooth, not sudden or jerky. Check this video out for the most common mistakes: kzbin.info/www/bejne/l2SueIpnqqmfotE

[@kimmytran9973]

Thanks for sharing! When dispensing liquid, I release at the first stop then second stop, but sometimes there’s liquid remaining. Do you have any idea on why this happens? Should I press it up and down to dispense the last liquid?

[@BioLabCollective]

Sounds like you’ve pushed past the first stop when drawing up liquid at the start? Too much liquid, otherwise there shouldn’t be any left over. Sure dispense all of it, but you should practice your technique more using the tips we talk about in the video.

[@kimmytran9973]

@@BioLabCollective thanks I will closely watch it next time!

[@kimmytran9973]

@@BioLabCollective thanks for the tips! My technique has improved alot. Another question- for positive displacement pipette instead of air displacement pipettes like these , do positive displacement pipettes have first and second stop? I have quite a bit of trouble using them not sure if I use them correctly.

[@BioLabCollective]

Yes they should have first and second stops too - depending how how they’re tuned you may not need to push to the second stop to dispense all the liquid? The second stop may just be reserved for ejecting the tip

[@zbigniewrozynek5121]

What about the reverse pipetting? The standard pipetting technique (that you present) is not good for some liquids.

[@BioLabCollective]

Reverse pipetting is very useful, but not my first recommendation if you’re new to pipetting. It’s hard enough to master the standard technique for most people. Maybe a topic for a new video!

[@gkum6067]

How to do avoid bubbles while pipetting and if bubbles come how to pipette the sample from those bubbles.

[@BioLabCollective]

Most common problem is pressing down too quickly when you are drawing up the liquid. It takes practice to do this smoothly - will cover more tips in a follow up video

[@skazka3789]

When I'm pipetting smaller volumes like 2 uL, often the drop does not want to leave the pipette and is stuck to the tip

[@BioLabCollective]

Pre-wetting the pipette tip before aspirating any liquid may help? Depends on the viscosity of the liquid too

[@skazka3789]

@@BioLabCollective thanks for your advice. btw i watched another vid where u say u wake up at 5 am. can i ask what time you sleep lol

[@BioLabCollective]

@@skazka3789thankfully 5am wakeup is not everyday! I don't get to sleep much unfortunately, hoping to change that in the new year.

[@jaynethmi]

When i used 2nd stop produce a air bubble. What is the reason for tht?

[@BioLabCollective]

You can try immersing the pipette tip in the liquid before you draw up any liquid. The speed at which you push down on the plunger can also affect bubbles?

[@jaynethmi]

@@BioLabCollective thank you 🙂

[@Oniku-niginigi]

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