I am really scared. I have been trying to perform an assay for last 5 monhts.. But the data are not reproducible at all. I am very much scared. The supervisor also got angry on me...what will I do? I have modified lots of factors, considered several things..now I am really frustrated. feeling nowhere..is it a common feeling. BTW I have just finished my first year.

How many times were you able to produce the results previously? Or were the results once-off so far? I assume you've looked into batch numbers and expiry/best before dates of all your reagents and assay components?

What kind of assay is it? I've had endless reproducibility probelms with HPLC; sometimes it's the most silly little thing that affects your results.

try not to worry: this is a very common feeling! Lab work is an absolute joke - there may appear to be a small handful of variables to manipulate, but in reality its not as simple as that. There are SOOOO many little variables that can have an affect on your results (e.g. ambient temperature in the lab; where you sit to do the work in the lab; contamination from something living on your lab coat; the fact that you might have sneezed 5 minutes before setting up your experiments!)As juno said, they are silly little things.

it may not be ideal, but the only way to solve the problem is to do the lab work along side someone with more lab experience. I personally HATE doing this, because i feel like im a useless 12 year old child again! But in the end, you wont regret asking for help.

thanks all for helping me out.. but I am still there, I peformed the radiolabelled binding assay last week again. still its not giving good scathcard curve.. last night i was thinking of quiting...I am so p**sed of..

Firstly I'd troubleshoot as said above.
In general for my sort of work (may/may not apply):

chemicals can have impurities/contaminants/use by dates/stored incorrectly and changing brand may help
glassware may be dirty or have a contaminant
there may be something limiting the reaction/binding kinetics
temperature/pH/buffer/cofactor may be needed
changing the concentrations of reagents may help
There could be an inpurity in your sample acting as an inhibitor
If another person gets the same results it's not your technique

If you can get a control to work then it's that system, I'd seriously consider this if you haven't e.g. if on a protein buy/find a sample of a cheap generic protein that works
You could characterise your sample possibly to check it is what it is supposed to be. I had a friend who didn't check the pH of a sample from a collaborator and the collaborator was wrong.

Finally your results may be perfectly valid, it might be that there's a scientific explanation for why it doesn't work specific to that system. Maybe there is a different technique to show the same thing, or support what you are trying to show

I was in exactly the same situation last year. I had been doing PCR on the same 5kb of DNA for months and got one fraction out of the five I wanted.
So I sat down with my supervisor and told him that I really didn't want to do this anymore! And he agreed - there are far better uses of my time. So I think you should do this. Ask your supervisor if there's any other experiments you can do to show the same thing or if you can go in a slightly different direction.
I felt totally depressed about my project this time last year (I'm in the middle of my 2nd yr now) - I had no results and no explaination as to why. But over the last couple of months everything has started to go right for me - I've so many reproducible results now I can barely keep up!

BTW, I'm not bragging, I just wanted you to know that things will get better, and you will have something to write up at the end! :)

hi,dont know whether this will helpp but ive been doing a radioactive binding assay using tritium. I was measuring IP3 production.Basically to test whether the whole thing was knacked i established my standard curve using triplicates. I then bought in some IP3 and made it up to known concentrations say 1M I then did the assay using that sample and did a count reading and extrapolated to work out IP3 concentration to see if it came out as 1M-if you dont get 1M theres probably some issue with the kit rather than you doing something wrong!!this is a lot more likely,these kits are notoriusly awkward,hope this helps!

actually don`t be scare...believed urself and motivated it by ur courage...

Believe in yourself, just keep in mind you have to finish no matter what!!!
You are just in your second year so, don’t worry just stay focused by preparing a log – write-down everything you plan to do for a week, try following the schedule and revise it repeatedly. Introduce some variety in your research, such as reading literature or working on a model or thinking about an article which you would like to publish in future and so on.

thanks to all of you who have replied me , encouraged me and helped me to sort it out. Yes, I am sticking to it..and will be hopefully...