Gram-Positive or Gram-negative? That is the Question

So it is the start of another week and we started by checking on the swab plate we made last Thursday.

Our culture

Today we did a staining process which involved a lot more steps and a three different stains. Before the we start staining, we have to fix the sample again just like last week. So we started with a water droplet. Then we take a small sample of bacteria, place it in the water on the slide, and spread it out over a good portion of the slide so as to get a very thin layer.

Spreading the bacteria

Once this air dries we seal the sample to the slide by heat. Now let the staining begin!

Ready for some color!

Well, that was a bit to much color

I caused a bit of a mess right at the start. One of the stains I was opening splashed everywhere and all over one of my hands! With lots of rubbing alcohol and lots of rubbing I managed to have only a few faint purple spots left. The table however was not as lucky. Anyway, back to the staining process. First we used crystal violet stain, covering the sample for 20 seconds. Using water (always deionized) Jessica washed off the stain and placed it back on the rack for the next color.

Violet stain after rinsing

 Next was Gram's iodine which has a yellowish color to it. This one sat for a minute. (The excitement is building!)

Gram iodine stain

Again, this was rinsed, but in between that and the last staining we decolorized the slide using 95% ethanol. This was rinsed and finally the last stain, safranin, was applied for a minute

Finally that last stain!!

The final rinse

Now we can see if everything we did was correct! This is what we saw:

The majority of the sample was gram-negative and it also contained many endospores. We may have also over heated it, so in Thursday we are going to redo the staining and see what results we get. See you then!!