Pipette Calibration and Cleaning

in order to calibrate pipettes you need several things the first thing you need is a pipette calibration SOP this is ours also you need a form to write your documentation your results in this is the way ours look this is transferred to an excel file that automatically calculates our values you need an analytical balance our analytical balance has a volumetric flask inside of it you also need a beaker with a NIST calibrated thermometer you need the actual pipette itself and then you need pipette tips lastly you're going to need some gloves to handle all of this this is the pipette we're going to be calibrating today and the lowest setting on here is 100 microliters noted by the hundred right here and then the highest setting is a thousand microliters as you can see it goes all the way up to 1000 so those are the two of the settings will be doing measurements on will also be doing 500 microliters which is right in the middle of this just so we can get a good accurate reading on how well this pipette is calibrated there's also a serial number on here it's going to be right here you can see it says 2 5 6 6 5 5 that's the serial number you'll be recording on just so we can track which pipettes we're doing calibrations on now we're going to discuss how you adjust the volume you'll be dispensing with the pipette er with the Eppendorf there's a button on the side that you need to press then you can rotate the knob to the appropriate volume in this case we're going to go from 963 to a thousand microliters now we're at a thousand microliters this will be the volume that is dispensed after you dial in your number you release the knob and it locks it in in order to put a pipette tip on we have our pipettor that we're going to be calibrating and all you do is you just take your pipette find the tip that you want and just push it in pretty hard make sure that it's not going to fall off and here you go your view tip on your pipettor there are two stops on a pipette so you can feel it there's a first stop and then there's a little bit further which is the second stop I'll do that again so there's the first stop and the second stop this is a large volume so you'll be able to actually see how the pipette goes down for the first stop and then there's actually a bigger jump but for a smaller volume you actually won't be able to see it as much it'll just be a feeling that you have when you're actually getting the volume so to be able to get our water sample we're going to go down to the first stop put our pipette in here and take some logs that was the first stop in order to get the volume in order to dispense your volume you're going to go down to the second stop in here a little click different pipetters have different ways on getting the tip off of the pipettor so on this particular one we're talking about the first stop and the second stop if you go a little bit further and kind of just push all the way down it releases the pipette tip now on this model there's actually a different mechanism all together for releasing it so this is the one that we were using to get the volume but to really set there's this knob right here put in here and get right down it takes the pipette tip off when you're getting your volumes sometimes some water can be ejected outside of the pipettor and thus can actually throw off our reading so when this happens all we do is we take a kimwipe and wipe the tip off and now we're good to go also sometimes when you're getting the volume you'll see a little bubble in the tip to see how the water doesn't go all the way down to the tip and this is going to also throw off your volume so when this happens we just need to take all the water out of the pipette tip and start over again so after we've dispensed the water out of the pipette sometimes there is a little bit left over and this is volume that's actually still left in here so if we try to get another on like five hundred microliters it's actually going to be a little bit more than factoid microliters is this water is still stuck in here so when this happens we will just take a new tip before we start actually taking some measurements we're going to fill out our form first basic things that you'll need is a date who's doing the calibration what location the pipettor came from the model number which is located on the pipettor for example we're doing the Eppendorf reference the serial number which is on the top right near the knob where you change the volume you're showing the volume range the pipette which is also on the knob this one is 100 to 1000 microliters I also put a conversion up here so we know one mil is 1000 microliters for this particular form the Tesla needs to be a milliliter so I already went ahead and converted it so the 100 microliters is going to be 0.1 mililiters and so forth um this one's going to be 0.5 milliliters this one is 1 milliliter which is a thousand microliters so we're starting out with our calibrated balance and the first thing we're going to do is put our volumetric flask in would open it up as you can see there's a weight that's showing on here we actually want to zero this and make it zero so it will start weighing the water inside and not we don't want the volume of the class to show so we'll zero this and it will show as zero weight and that's where we need to start from so we're going to take our first volume which is a hundred microliters and we're going to put it in our volumetric block well is it and we will record this value here which is 0.1 0 3 9 grams and we'll put that right at the hip in our first column and we will be repeating this process on either five times or ten times depending on your SOP after we've gotten our first value we're going to be zero or we tear it serve back to zero grams so you can record our next volume so take another 100 microliters and this time it's point one zero six eight so I'll go ahead and report that on for the 100 micro liter sample I have actually done it five times I have five replicates here and now we're going to move on to the 500 microliters or half a mil now that we're doing 500 microliters I have set the pipette to see 500 on the display and now we're going to repeat taking the five replicates of the weight of the putter so we'll do the same thing that we did for the 100 microliters so now that I've done the 0.5 mils five times I want to move on to do the 1 mil now we're going to do our highest measurement on the pipette which is a thousand microliters or one milliliter we're going to go ahead and do and repeat it the same way we did for the one hundred and five hundred milliliters use the same protective that's fine and then grab one thousand leader microliters make sure the room and this should be very close to one gram and looks like it's 0.99 to five grams and we'll go ahead and repeat that same thing so all five of them are done so now we're going to do the highest measurement of our pipette which is a thousand microliters or one milliliter and we're going to go ahead and drop the 1,000 meters and make sure our scale is zeroed with tears we'll go ahead and for this value which is 0.99 for five grand so now that we have all the values that we need for our calibration we are going to go ahead and take this to the computer and enter these values into Excel and these will tell us whether or not our pipette has passed or failed calibration all right so before this calibrating we want to make sure the pipe that is clean doesn't have any residue we can open it up there is no closure looks clean lubricated but we can use isopropyl alcohol or ethanol to clean pipette okay so I'm going a little bit of the outside and inside before I start calibrating there are some residue might need cleaning this is 70% ethanol each pipette has an instruction how to get clean this eppendorf the instruction can be the box it's got all the box cover oil that the duplicate orange they pack together not that dirty is still every six months I open up and clean it up outside like everything else all the residue all the germs cases of Israeli is new so it's got enough lubrication on the boring otherwise I have to look at me before calibration I gotta see the need any adjustment there is enough for a judgment I can't read enough I can turn into the clockwise of the other way I want to see to get it to the calibration that wait I needed I usually like 200 percent accuracy but our spreadsheet allows 5 percent deviation for some method clean water act used 2 percent for micro s 2.5 or 3 percent it depends your cure program what percentage the tighter the accuracy the 1 percent is the most accurate one

Channel: Arizona Department of Health Services

Views: 179,456

Rating: 4.6474819 out of 5

Keywords: ADHS, Arizona Department of Health Services, Arizona State Laboratory, pipette, pipette calibration, pipette cleaning

Id: MBq55FtOzN4

Length: 12min 22sec (742 seconds)

Published: Tue Dec 17 2013