Mol bio lab

Question 1

is concerned with the organizational process and the conditions under which laboratory studies are planned, performed, monitored, recorded, and reported.

Answer 1

Good laboratory (GLP)

Question 2

Closeness of agreement between a measured quantity value and a true quantity value of a measurand

Answer 2

ACCURACY

Question 3

Particular quantity intended to be measured
Example: vapor pressure of a given sample of water at 20°C.

Answer 3

Measurand

Question 4

Also called “dead volume”, the air cushion is the volume of air located between the lower part of the pipette piston and the surface level of the sample.

Answer 4

AIR CUSHION

Question 5

Measured portion of a homogeneous entity. A general term referring to multiple samples of any solution, mixture, etc.

Answer 5

ALIQUOT

Question 6

An instrument for delivering predetermined volumes of liquid from a reservoir. The reservoir may be integrated into the instrument or connected externally.

Answer 6

DISPENSER

Question 7

Rounded or approximate value of characterizing quantity of a measuring instrument or measuring system that provides guidance for its appropriate use.
Examples: a) 1 L as the value marked on a single-mark volumetric flask, b) 100 μL as the setting appearing on the volumeter of a pipette.

Answer 7

NOMINAL VALUE

Question 8

Closeness of agreement between indications or measured quantity values obtained by replicate measurements on the same or similar objects under specified conditions.

Answer 8

PRECISION

Question 9

An instrument for transferring a predetermined volume of liquid from one vessel to another. A pipetter is not connected to a reservoir

Answer 9

PIPETTE/ PIPETTER

Question 10

The appropriate representative part of a liquid to be analyzed. The term “test sample “is used when necessary to avoid confusion with the statistical term “random sample from population”

Answer 10

SAMPLE

Question 11

The portion of the sample that is retained in the instrument after sample delivery and that may affect subsequent samples.
NOTE: Carryover from a positive displacement pipette is less than from an air- displacement pipette.

Answer 11

SAMPLE CARRYOVER

Question 12

Total volume and temperature range, as well as ambient conditions, for which instrument performance is specified.
Note: do not select volumes outside recommended limits.

Answer 12

WORKING RANGE

Question 13

Measurement precision under reproducibility conditions of measurement.

Answer 13

Reproducibility (of Results of Measurements)

Question 14

Types of Pipettes:

Answer 14

Air displacement
Positive displacement

Question 15

pipetting is highly accurate for standard pipetting applications.

Answer 15

Air displacement

Question 16

pipetting is based on direct contact of the piston with the liquid.

Answer 16

Positive displacement

Question 17

Recommended for aqueous solutions, such as buffers, diluted acids, or alkalis, this technique is commonly used when pipetting and mixing a sample or reagent into another liquid.

Answer 17

Forward Technique

Question 18

This technique is commonly used with air displacement pipettes, and is recommended for precisely pipetting small volumes. Reverse pipetting avoids the risk of sample splash, foaming, or bubble formation.

Answer 18

Reverse Technique

Question 19

This technique is intended for repeat dispensing of the same volume, and is ideal for adding reagents into tubes or wells of microplates.

Answer 19

Repetitive Pipetting Technique:

Question 20

is a multi-purpose tip for many laboratory applications with a variety of performance requirements that range from high accuracy to reagent dispensing with greater tolerance.

Answer 20

A standard tip

Question 21

Cross-contamination from pipetting is a constant concern within a lab. Two options exist within the Thermo Scientific Portfolio: Filter Tips and Barrier Tips

Answer 21

Sterile filter and barrier tips

Question 22

utilizes pore size and treacherous path technologies to help control liquid from accidentally splashing the inside of a pipette.

Answer 22

A filter tip

Question 23

utilizes a self-sealing technology to prevent liquid from passing and accidentally splash the inside of a pipette.

Answer 23

An ART Barrier tip

Question 24

are recommended for low volume applications in genetic studies, forensics and PCR or anytime contamination is a concern.

Answer 24

Filter and Barrier tips

Question 25

Utilizing polymer technology makes the inner surface of the pipette tip more hydrophobic, resulting in a reduction in sample loss due to adhesion. Benefits include improved sample delivery and conservation of expensive reagents.

Answer 25

Low retention pipette tips

Question 26

are designed for unique pipetting applications to save time, reduce contamination, and increase accuracy, precision, and productivity.

Answer 26

Specialty tips

Question 27

feature a distal end orifice that is nearly 70 percent larger than that of a standard pipette tip. These tips provide the added flexibility required for handling difficult-to-pipette samples. They are designed for researchers working with macromolecules like genomic DNA and are especially critical for transferring fragile cellular samples such as macrophages, hybridomas, and hepatocytes, as well as other viscous materials.

Answer 27

Wide orifice tips

Question 28

allow you to access the bottom of test tubes, reagent bottles, flasks, and other vessels without touching the shaft of the pipette against the side of the tube. This adds a layer of security to protect samples, and virtually eliminates the chance of carryover contamination. The longer tip length allows you to reach the bottom of long or narrow vessels that standard tips cannot reach.

Answer 28

Extended length tips

Question 29

Loading acrylamide or agarose gels with standard pipette tips can be a time- consuming process. Use the round gel loading tips for agarose gels and specialized Ultra Round and Ultra Flat gel tips for your polyacrylamide gels to speed up the loading process. 8. Solvent-safe carbon filtered pipette tips are the best solution for handling the pipetting rigors of Combinatorial Chemistry. These specialized tips keep strong acids, bases, and aggressive organic solvents from causing pipette failures and critical inaccuracies.

Answer 29

Gel loading tips

Question 30

are the best solution for handling the pipetting rigors of Combinatorial Chemistry. These specialized tips keep strong acids, bases, and aggressive organic solvents from causing pipette failures and critical inaccuracies.

Answer 30

Solvent-safe carbon filtered pipette

Question 31

Pipette maintenance is done by either the manufacturer or the end-user. For maintenance, always check the manual and documentations that come with the pipette.

Answer 31

Pipette Basic Maintenance

Question 32

is a procedure used to isolate DNA from the nucleus of cells.

Answer 32

DNA extraction

Question 33

To obtain DNA in a relatively purified form which can be used for further investigations, i.e. PCR, sequencing

Question 34

Non-ionic detergent , Salt, Buffer, EDTA designed to lyse outer cell membrane, but will not break down nuclear membrane.

Answer 34

Cell Lysis Buffer

Question 35

is a chelating agent of divalent cations such as Mg2+. Mg2+is a cofactor for DNase nucleases. If the Mg2+is bound up by EDTA, nucleases are inactivated.

Answer 35

EDTA (Ethylenediaminetetraacetic disodium salt)

Question 36

it is usual to remove most of the protein by digesting with proteolytic enzymes such as proteinase K, which are active against a broad spectrum of native proteins, before extracting with organic solvents. Proteinase K is approximately 10 fold more active on denatured protein. Proteins can be denatured by SDS or by heat.

Answer 36

Proteinase K

Question 37

remove proteinaceous material.

Answer 37

Phenol/Chloroform

Question 38

is often used to store DNA and RNA. EDTA in TE chelates Mg2+ and other divalent metals ions necessary for most causes of DNA and RNA degradation, suppressing these processes. Tris is a buffering agent to keep the solution at a defined pH.

Answer 38

TE Buffer - Tris-EDTA Buffer: TE buffer

Question 39

which help in precipitation of DNA.

Answer 39

Ethanol or isopropanol

Question 40

This buffer will lyse cell membrane, nuclei are intact, pellet nuclei.

Answer 40

1.Cell Lysis Buffer

Question 41

The stages of the method are

Answer 41

Lyse Bind Wash Elute

Question 42

The cells of a sample are broken open with a lysis procedure

Answer 42

Lyse

Question 43

A buffer solution is then added to the sample along with ethanol or isopropanol. This forms the binding solution. The binding solution is transferred to a spin column and the column is put in a centrifuge. The centrifuge forces the binding solution through a silica gel membrane that is inside the spin column. If the pH and salt concentration of the binding solution are optimal, the nucleic acid will bind to the silica gel membrane as the solution passes through.

Answer 43

Bind

Question 44

The flow-through is removed and a wash buffer is added to the column. The column is put in a centrifuge again, forcing the wash buffer through the membrane. This removes any remaining impurities from the membrane, leaving only the nucleic acid bound to the silica gel.

Answer 44

Wash

Question 45

The wash buffer is removed and an elution buffer (or simply water) is added to the column. The column is put in a centrifuge again, forcing the elution buffer through the membrane. The elution buffer removes the nucleic acid from the membrane and the nucleic acid is collected from the bottom of the column.

Answer 45

Elute