S-STEM Scholar Anh Nguyen's Blog

  Introduction:      Unfortunately this week, Jessica, Kaylee, and I found an unusual growth curve in our 96 wells plate that we figured could be a sign of contamination. To go into deeper details, our negative control had only TGY but it showed an unusual growth curve that we might've guessed that there was a type of bacteria in our TGY and that it is contaminated.  Discussion:  Fig. 1  As shown in the results and our negative control, from the H wells, it only contains TGY but it showed a growth curve.  Fig. 2  Knowing this information, we decided to do a gram stain to see what type of bacteria contaminated the TGY. Dr. Tuohy suggested that the gram stain was gram negative and could perhaps been caused from a pipetting error since we have pipetted many times in the wells. Since this procedure failed, we will conducting a new plan and make new media.  Fig. 3  After talking and taking some advice from Jonathan, we decided to change ...

 In this week, I worked on a transformation kit.  Materials:  - two micro test tubes  - Sterile transfer pipettes - Ice  -Sterile loops  -Bacteria starter plate - UV lamp  - media plates - pGLO plasmid DNA Solution  Process:  1. First, label one closed micro test tubes as "+pGLO" and another "-pGLO" and place them in a tube rack.  2. Using a sterile transfer pipette, transfer 250 ul of transformation solution (CaCl2)  3. Place the tubes in ice.  4. Using a sterile loop, pick up a single colony of bacteria from start plate.      - pick up loop and put it in the +pGLO tube      - spin the loop until the entire colony is dispersed in the transformation solution (no floating chunks)      - place the tube back into the ice     - do again for -pGLO tube using a new sterile loop 5. Examine the pGLO plasmid DNA Solution with the UV Lamp. 6. Immerse a new sterile loop into the plasm...

 In this week, I learned how to make a Gram Stain. What is it is really how you can tell if a bacteria is contaminated or not.  Procedure:  1) Prepare bacteria on slide.     -  For bacteria in liquid media/culture, use about 7ug by micro pipetting and place them on slides.      - For bacteria on plate, first draw a circle on the slide to mark where you will be putting the bacteria on. Then, use a sterilized loop (using heat) to transfer bacteria onto slide. (Remember to use heat to dry the bacteria on the slide before the next steps.)  2) Stain the slides with crystal violet for exactly 1 minute . Carefully rinse with DI Water and avoid hitting inside the circle but also try to get most of the excess pigment off of the circle.  3) Now, bacteria should be bluish purple. Then, stain the slide again with iodine for exactly 1 minute . Carefully rinse again with DI Water.  4) Drop alcohol for exactly 7 seconds . Quickly rinse w...

 Week 4: Making TSB Broth Media and transferring it into 3mL test tubes In lab this week, I learned how to make different medias for bacteria to grow in. I will be mainly focusing on TSB Broth Media. It is a liquid media that holds up bacteria longer than HS Media (which only holds bacteria for around 2 weeks).  Objective:  I will be making TSB Broth and transferring it into these test tubes in 3ml each. Ingredients : - 500mL of distilled water (DI Water)  - 15 grams Tryptone Process:  - To start, since I need a total of 500mL of distilled water, I will start it off with only 400mL.  I added a total of 400 mL of DI Water into a 1000mL narrow mouth beaker.  - For the Tryptone, I measure about 15 grams on a gram scale.  - To top it off, I finally add another 100mL of DI Water to make a total of 500mL and to also clean the sides of the beaker for excess powder.  - I stir and mix well.  - Then, I split the 500mL into 2 smaller beakers; which...