Counting colonies help!

[deleted-852959]

I need help with counting colonies.
I used an app to count the colonies but now i need tell my teacher the measurement I used but all i had to do on the app was to take a picture of my agar plate and then count the visable colonies...but at the measurement of the app it just said "CUFs per plate"
I just counted the visable colonie sthat you can count with your eyes, but i dont know what unit to use when counting only visable colonies
Please help!

[deleted-744967]

Hmm, typically what we report is CFUs (colony forming units) on a plate, as your software did. Did you ask your teacher what they meant by 'measurement'? CFUs counted by eye using XX software seems like it would be good enough, but one thing you could do is measure the smallest colony you counted, in mm. Then you could say you included "all colonies greater or equal to Xmm in diameter". If you don't still have your plate, your best bet is to zoom in/out on the picture you took until the dish is 'life size', and then measure on your screen.
Did you have any colonies you didn't count? Like ones that had grown together into one mass? You could also say you did or did not exclude those in your count, and give your reasoning.
If that's still not what your teacher wants, ask them for a specific example, and come back and tell us!

[deleted-852959]

Thanks. In our science projects when we have to draw our tabels with our results in it...at the heading for the cell in our tabel wich in our case it was "Total visable colonies" she said we have to say what unit we used to count them, in brackets next to that heading...so i also dont understand what more she wants.

[deleted-852959]

Like...qe did our whole project and had to send it to her. Then she said it was a very good project and game some things we need to fix...then one of the things were to show what unit you used to count the colonies and add that to your result's table.

[deleted-744967]

Hmmm. So you reported your values in CFUs? Technically that is the correct unit, and you'd put it after your number, like you would mm for example. So if you just put 200 and not 200 CFU, then CFU is the unit you need to add.
You could also write it out on your table; like if you have a column in your table that you've labeled CFUs, instead spell it out as Colony Forming Units, and then put CFU after each number in the column.

But if you put in CFU and she wants a more traditional measurement, you could still measure your smallest colony on each plate and put on your table "all CFU >/= 1mm" for example. Or measure the largest and smallest and report something like
"0.5mm < all CFU < 3mm".

I hope that helps!

[deleted-852959]

I mean wow!! You guys are the best!
I appreciate it so much.
Thank all of you for helping children and teenagers that need help.

[deleted-744967]

Glad to help!