Ex 1

Question 1

are one of the standard laboratory equipment used to measure and transfer small volumes of liquids. These air displacement piston pipettes use disposable tips and allow accurate, precise, and rapid dispensing of various volumes.

Answer 1

The Micropipette

Question 2

Pipette tips capacities

Answer 2

Blue (100-1k ul)
Yellow (2-200 ul)
Clear (0.5-10 ul)

Question 3

an instrument used to sterilize equipment and supplies by subjecting them to high-pressure saturated steam at ___ around ____ minutes depending on the size of the load and the contents

Answer 3

Autoclave; 121 °C for 15–20 mins.

Question 4

Autoclave was invented by____ and its precursor, the steam digester was earlier created by _____.

Answer 4

Charles Chamberland (1879)
Denis Papin (1679)

Question 5

Autoclave literally means ___ referring to the mechanism that keeps the lid in place as the pressure is increased,

Answer 5

“self-locking”

Question 6

Autoclaves are used when decontaminating ___ or potentially
or sterilizing solids and liquids. Biohazardous items are
autoclaved to inactivate pathogens like _____.

Answer 6

biohazardous; bacteria, viruses, fungi, and spores.

Question 7

any device that spins at a high speed to press objects
outward with centrifugal force.

Answer 7

The Centrifuge Machine

Question 8

used to separate items in suspension.

Answer 8

Centrifuge Machine

Question 9

The centrifuge works using the ___ where the ___ causes more dense substances to separate out along the ___

Answer 9

sedimentation principle; centripetal
acceleration; radial direction

Question 10

an analytical instrument used to measure the intensity of light as a function of its wavelength.

Answer 10

The Spectrophotometer

Question 11

The Spectrophotometer measures what

Answer 11

It measures transmission or apparent reflectance of light as a function of wavelength.

Question 12

According to Beer’s law, the ___ absorbed by a medium is proportional to the ___ or solute present.

Answer 12

amount of light; concentration of the absorbing material

Question 13

The sequence of events in a spectrophotometer can be listed as follows:

Answer 13

● The light source enters the sample against a blank sample.
● The sample absorbs light.
● Then the detector determines how much light is absorbed by the sample (equivalent to the amount of light that reached the detector relative to blank or no absorbed light by blank
substance).
● The detector then converts the amount of light absorbed by the sample into a number.
● The numbers are plotted straight away, or are transmitted to a computer to be further manipulated.