Body Ink Effects on Microbial Survivorship

Kevin FrankolaPittsburgh Central Catholic HighschoolGrade 11

Tattoo Ink

24% of Americans between the ages of 18-50 have a tattoo

One of the more common types of tattoo ink was selected, an ink containing an Azo Compound.

Azo Compounds are characterized by the functional group: R-N=N-R‘

R and R' can be either aryl or alkyl.

Tattoos

Tattoo ink is injected underneath epidermis

Tattoo ink permanently stains dermis

The dermis contains sweat glands, sebaceous glands, and some sensory cells

The ink could possibly interfere with the role of these cells.

Escherichia coli

Most researched prokaryotic cellGram negativeFound in the intestines of warm-blooded animalsProkaryotic cells lack a nucleus, their genetic code wrapped in a bundle in the center of the cellStrong enough chemicals can alter DNA causing potentially fatal mutations

Yeast

The most researched cellEukaryotic cellFungi cellDominate ocean fungal diversityUsually 3–4 µm in diameterHave the stronger relationship to Human Skin cells, both being Eukaryotic

PurposeHumans absorb many chemicalsCan chemicals that come into contact with the skin have harmful effects?The purpose of this experiment was to determine if tattoo ink has a significant effect on microbial growth. Prokaryotic cells and eukaryotic cells were used, Escherichia coli and Yeast respectively

Hypotheses

The alternative hypothesis is that any variation in survivorship will not be due to chance, but rather the ink has an effect on microbial survivorship.

The null hypothesis is that the ink will have no effect on microbial survivorship and that any variation in survivorship is due to chance alone.

MaterialsCulture of yeast cells at 10⁵ cells per ml. Culture of Escherichia coli at 10⁵ cells per ml.164.56ml of SDF1ml of tattoo ink16 tubes32 YEPD agar plates (yeast)32 Nutrient agar plates (E. coli)Micro pipettes (1000μl and 200 μl)BurnerVortexSpreader BarEthyl alcoholSterile tips

Procedure

1. Saccharomyces cerevisiae was grown overnight in sterilized YEPD media.

2. A sample of the overnight cultures was added to fresh media in a sterile sidearm flask.

3. The culture of yeast was incubated at 30°C until a density of 50 Klett spectrophotometer units was reached. This represents a cell density of approximately 107 cells per mL.

4. The culture was diluted in sterile dilution fluid to a concentration of approximately 105 cells per mL. The following tubes were created:

5. The tubes were incubated at room temperature for 30 minutes. 0.1 mL of each suspension was then plated onto YEPD agar plates. The plates were incubated at 30C for 48 hours. The resulting colonies were counted (each colony was assumed to have arisen from one cell.

Procedure (Continued)6. 100μl of yeast culture were pipetted into each of the 8 yeast-designated tubes.7. 100μl of Ecoli culture were pipetted into each of the 8 Ecoli-designated tubes. 8. 100μl of a tube’s solution was pipetted onto a plate.9. The spreader bar was sterilized, then used to evenly spread solution over the plate. 10. Steps 8-9 were repeated for every tube 4 times, totaling of 32 plates of Ecoli cultures and 32 plates of yeast cultures. 11. The plates were incubated for 36 hours.12. The colonies on the plates were counted the following day.

Yeast

E. coli

0ml 0.01ml 0.1ml 1ml175

180

185

190

195

200

205

210

215

220

225

Yeast Survivorship, Series A

Concentration of Ink

Num

ber o

f Col

onie

sP value = 0.311468

0ml 0.01ml 0.1ml 1ml0

50

100

150

200

250

Yeast Survivorship, Series B

Concentration of Ink

Num

ber o

f Col

onie

s

P value = 0.078993

0ml 0.01ml 0.1ml 1ml0

50

100

150

200

250

215.667198

163175.333

E. coli Survivorship, Series A

Concentration of Ink

Num

ber o

f Col

onie

s

P value= 0.509234

0ml 0.01ml 0.1ml 1ml0

50

100

150

200

250

300

255

204.3333

226.5

263.333

E. coli Survivorship, Series B

Concentration of Ink

Num

ber o

f Col

onie

sP value =0.716818

Conclusion

The results appear to show the ink had no significant effect on the survivorship of yeast and E. coli.All four of the ANOVA P values indicated that the null hypothesis must be accepted. The ink had no effect on microbial survivorship and any variation in survivorship was due to chance alone.

Limitations and Extensions

10% concentration would be highly increased

Different colors would be tested Different species Test on macro organisms

References

www.mayoclinic.com www.wikipedia.org www.fda.gov www.chemistry.about.com www.tattooology.com