Biology
Ms. Haut
1.
2.
3.
Add 1 ml (10 drops)
of Benedict’s solution
to the test tube.
Add 8 drops of
sample solution to a
test tube.
Heat the mixture in a
boiling water bath for
10 minutes or until
the control turns
orange.
negative
positive
Initial Color
http://media.photobucket.com/image/benedict%252527s%20test/sapp
hirex/Char009.jpg
Final Color
http://media.photobucket.com/image/benedict%252527s%20test/sapphirex/C
har012-2.jpg
http://www.umanitoba.ca/faculties/science/biological_sciences/lab2/images/BenedictsTest-1.jpg
2.
3.
4.
Place a 1 mL of the
sample solution into a
test tube.
Add 5 drops of Lugol’s
solution (IKI) to the
test tube.
Swirl the test tube to
mix.
If the solution turns
bluish-black in color,
you will know that
polysaccharide is
present.
http://iws.ccccd.edu/biopage/BioLab/Unit%205/Starch%20test.jpg
1.
positive
negative
http://www.webexhibits.org/causesofcolor/images/content/emerald/DSC03426Z.jpg
Note the change of the iodine to black on the potato
(right) but not the apple (left). Potato contains starch,
but apple does not.
2.
3.
Add 1 ml (10 drops)
of Biuret reagent to
the test tube.
Put 1 ml of sample
in a test tube.
If the solution turns
purple in color, you
will know that
protein is present.
http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%2
0101%20laboratory/chemical%20composition%20of%20cells/biuret.jpg
1.
Positive
1.
2.
3.
Using the spatula,
smear some fat onto a
piece of plain paper.
Ensure that the paper is
not glazed or waxed.
Hold the paper up to
the light or window,
attempting to look
through the spot formed
by the fat.
If a greasy spot
remains after the paper
dries, fats are present.
2.
3.
4.
5.
Place 1 ml of your
sample into a test
tube.
Add 1 ml of distilled
water to the test tube.
Place 1 drop of
Sudan III solution into
your sample.
Swirl the test tube to
mix.
If the solution stains
red, fats are present.
http://biology.unm.edu/ccouncil/Biology_124/Images/sudanIVtest.jpeg
1.
 Which
test produced
these results?
• Benedict’s Test
 Which
macromolecules
does it test for?
• Monosaccharides
 Which
A
B
test tubes
indicates a positive
result? How do you
know?
 Which
test produced
these results?
• Sudan III Test
 Which
macromolecules
does it test for?
• Lipids
 Which
A
B
test tubes
indicates a positive
result? How do you
know?
 Which
test produced
these results?
• Lugol’s Test
 Which
macromolecules
does it test for?
• Polysaccharides
 Which
A
B
test tubes
indicates a positive
result? How do you
know?
 Which
test produced
these results?
• Biuret Test
 Which
macromolecules
does it test for?
• Proteins
 Which
A
B
C
D
test tubes
indicates a positive
result? How do you
know?