Microbio: Unknowns

I suppose to start Case Study this or perhaps next week, too. Not sure what to expect yet, but I am crossing my fingers for something simplier. At this point I don't much to comments. Just hope that your assignment will go smoothly.

So we just started doing our unknowns this week and Im a bit freaked out. I thought it would be kinda easy, but the first day I couldnt get my gram stain and microscope right... UGH. Yeah Im pretty sure mine is gram negative because it was pink, but I couldnt make out if they were rods or cocci.

Anyways, just wondering who else is starting unknowns and if we could share some tips and links to help us out.

My professor is counting this as our final so its reeeallly important. Also this girl in the nursing program told us that she found that the unknowns were more important than what she thought, now that shes in the program.

So I look forward to hearing form u guys.

we won't be starting our unknowns for a couple more weeks I am very nervous about it also. Do you work in groups, partners or alone? we are working with partners but we can't pick them its random drawing (

my professor is making us work completely alone.. I totally hate the vibe that its creating...and its making it more stressful I think. :uhoh21:

Figuring out our unknowns was my most favorite part of micro! We were allowed to ask each other questions and get opinions but we were not allowed to ask our instructor anything (well we had to ask for our media but that was it!). Yes it was nerve racking but fun. When I did my unknown, gram stains were a "freebie" and we could do it as many times as we wanted to. Of course we had to explain why we did it each time but that wasn't so bad. If you can, I would do it again just to double check your work and hopefully this time, you won't take too many specimen so you can see the size. Good luck!!!

my professor is making us work completely alone.. I totally hate the vibe that its creating...and its making it more stressful I think. :uhoh21:

I prefer to work alone I hate working with people I don't know.

Figuring out our unknowns was my most favorite part of micro! We were allowed to ask each other questions and get opinions but we were not allowed to ask our instructor anything (well we had to ask for our media but that was it!). Yes it was nerve racking but fun. When I did my unknown, gram stains were a "freebie" and we could do it as many times as we wanted to. Of course we had to explain why we did it each time but that wasn't so bad. If you can, I would do it again just to double check your work and hopefully this time, you won't take too many specimen so you can see the size. Good luck!!!

I am not as worried about figuring out the unknown as I am at having to write the scientific paper about it all, she has a huge long procedure for doing this and I am so awful at writing papers I would rather just do the work and turn it in. Thats what has me stressed.

I preferred working alone, there were a few students in the class that had kept coming to me for help, and I was able to complete my assignment by myself, quickly and efficiently.

That being said, the NIH site and Microbe-Wiki both have pictures that may be helpful to you.

Google both terms for the links- Good luck =)

We did unknowns in our class last semester. The professor gave us a plate with a mixture of gram positive and gram negative. We had to separate them and then identify them. The easy part was that he have us a list of what they could possibly be (one of six G+ and one of six G-).

As I remember, certain media were selective for Gram stain, and that's how we separated the two. I don't remember which was which, but you could probably look it up in your book and then plate your bugs out on a G+ and G- selective plate and see what it grows on to confirm.

Some of the bacilli are stubby little things and hard to tell from cocci.

Good luck.

The paper for me wasn't so bad. Our instructor gave us guidelines and basically told us everything he wanted to see in it. I would start working on your paper asap though. I waited on mine and had wished that I didn't. I found it hard to go back and justify why I did some of my first tests. The paper took time and was long (mine was about 15 pages including cover page) but don't let it get you down. Start on it early and it won't seem like such a huge task. Good luck.

I took microbiology and received an A in the course.

Gram staining is the most difficult part of the lab.

Try to ask your professor how long culture was sitting for. If you a a 72 hour specimen, the gram stain is not going to work whether it is a gram negative or gram positive bacteria. If you have a 24 hour old specimen and the stain is pink, then you know you have a gram-negative bacteria. The reason why this is is because gram-negative bacteria cell walls aren't thick and can't hold the primary stain (crystal-violet), when the counterstain (safranin) is added. A 72 hour-old culture will enter into the stationary phase which means that you will start seeing some dead bacteria. This means that when you stain the culture, you will see both blue and pink. This is something you want to be careful of. The professor will have you look into the microscope to see what stain the culture is. Just remember, try not to think about what the bacteria is. Just look at the stain. If you see pink, it is gram-negative. If you see blue-violet, it is gram positive. If you see both blue and pink, it is gram variable. And rememeber, ask the professor how old the culture is. This will give you a clue of what stains to expect.

well, I redid my gram stain and Im pretty sure its gram + cocci. the background is pinkish or white and the bacteria are purple cocci's ... so im thinking gram +

Ill be running various tests to determine exactly what bacteria it is and also to verify my assumptions, just to be sure. If it proves to definitely be G+ then thats great news because out of the bacteria we have been testing and studying only 3 are G+ and there are about 10 or more G- bacteria... so it slims it down greatly.

Anywho Im happy... ill have to wait until after spring break to get my results back... then ill be able to futher plan out what im trying to look for when I see what kind of results I get.

Its really exciting actually... like playing detective.

Its really exciting actually... like playing detective.

Yeah, that's how we felt too. A lot of my classmates didn't like the labs until we did the unknowns.