Yes, pipeting is often challenging for beginners.  I would suggest having your trainee use a PCR master mix (combining the water, buffer, dNTPs, taq, primers or template) then adding the needed last ingredient (usually primers or template, depends on what you are testing for) to individual tubes.  That way they are less likely to leave out reagents in the individual tubes. 

If you are trying to train them on good pipeting usage, you could have then pipet and weigh different volumes of water (1 ml is 1g so the math is straightforward).  It's a nice way for them to learn both pipeting and how to read a balance. 

I agree with you Godfred, especially in a real time PCR more than in an end-point PCR

Yes, very true. It is usually my first issue to train a begginer on how to use the different pippets, with the emphasis on multichannel pippets. Sometimes because of the little volumes involved, they pippet nothing, and if it is a multi channel pippet, some tips do not pick  while others pick and they may not be aware until the results are out which is too late.

Yes, pipeting is often challenging for beginners.  I would suggest having your trainee use a PCR master mix (combining the water, buffer, dNTPs, taq, primers or template) then adding the needed last ingredient (usually primers or template, depends on what you are testing for) to individual tubes.  That way they are less likely to leave out reagents in the individual tubes. 

If you are trying to train them on good pipeting usage, you could have then pipet and weigh different volumes of water (1 ml is 1g so the math is straightforward).  It's a nice way for them to learn both pipeting and how to read a balance. 

the beginners often misses one of the components such as dntps or polymerase.

they aslo forget to change their disposable pipette tips that cause contamination. While running in agarose gel, at times they may miss ethidium bromide,, finally they conclude that PCR didnt work. 

It'll help to make the master mix for your samples you have + 1 extra depending on the number of samples you have. Say you have just one sample and you need to add 0.2ul Taq DNA Polymerase, that's pretty difficult to pipette so making the master mix for 2.5 samples then using just what you  need will be preferential.

Another technique one of my instructors used was to have students sketch out a picture of what the gel would look like if all of the reactions worked as expected (which lanes would have bands, how many, what size(s).  It really does help for the data interpretation side of things (which is often another main challenge for new students). 

Yes, it is. For qPCR you can even see differences if you compare automatic pipetting with pipetting by hand (same experimentator, experienced and accurate).

It may happen. For the beginners or even laboratory experienced staff I would recommend to prepare the master mixes, the best method to avoid pipetting the small amounts of reagents as the main source of errors.

yes, pipetting is the one of the most important thing during PCR. The use of the automatic pipette may give accuracy to beginners.

Pipetting skills are important to develop. In qPCR applications however robust changes in gene expression are seldomly attributable to incorrect pipetting. To get a difference of 1 Ct through inaccurate pipetting, you would have to add for example twice the volume of your template, which is quite unlikely to occur just by poor pipetting skills. The use of master mixes is very important I agree

Yes, I think it is. Using master mixes can help, The use of a housekeeping gene (such as 18sRNA or GAPDH etc) is a good indicator of how accurate one's pipetting is. 

THE DIFFICULTY CAN BE OVERCOME BY USING AUTOMATED PIPPETTE

very important. so beginners should practice with tracking dye or water. After getting constant volume repeatedly one should use pcr mastermix.

Hi!

Yes, pipetting is the one of the most important skills to perform a good PCR. I surely agree that a wrong pipetting will change the final result. I believe that this kind of erros  with beginners may occur due to poor pipetting by hand. Pipetting small amounts of reagents is the main source of erros and this may be corrected by training them using an automatic pipette.

Good luck!

Pipetting errors are important - but not nearly as important as manufacturers of real-time PCR machines like to suggest. PCR is a pretty robust reaction and a 10% pipetting error is unlikely to make any difference; in many cases a 25% error will be tolerated. However, I've seen some really terrible pipetting technique in my time - students holding pipettes horizontally (or even inverted!); students who can't distinguish the stop point from the shootout; students who can't spot when the pipette tip isn't properly affixed to the pipette - and wonder why it drips!. 

On the other hand, accurately pipetting volumes less than 2 ul is challenging for anyone. I try to design PCR protocols so that such small volumes are avoided. 

I think it is important for pipetters to get a sense of what different volumes look like. Most problems are caused not by pipetting 4.5 ul instead of 5 ul, but by gross errors, like pipetting 10 ul instead of 1ul. 

Yes it is - but not to the degree that some product manufacturers like to suggest. PCR is a very robust reaction and you can vary most of the components by +/- 20% with very little effect. 

That said, some beginners can be amazingly clumsy with pipettes and make gross errors, particularly when pipetting volumes < 5 ul. Knowing what 1 ul, 2 ul, 5 ul and 10 ul actually look like makes a big difference. 

most pipet producers have training session on how to use a pipet and also on their website you can find tips on good pipetting. The booklet that comes with the pipet also contains instructions. And you need to regular check your pipets if they need to be adjusted by checking the volume on a balance.