molbio Flashcards
what pipette is generally used in molecular biology laboratory
micropipette
all of the following are not examples of a measuring or graduated pipettes except:
a. mohr, pasteur, kolmer pipette
b. micropipette, mohr, bacteriologic pipette
c. serologic, bacteriologic, volumetric pipette
d. pasteur, ostwald folin, volumetric pipette
b. micropipette, mohr, bacteriologic pipette
all of the following are examples of a transfer pipette except:
a. micropiptte, pasteur, ostwald folin pipette
b. micropipette, mohr, bacteriologic pipette
c. pasteur, ostwald folin, volumetric pipette
d. none of the above
b. micropipette, mohr, bacteriologic pipette
multi-channel micropipettes have different variants and those are?
why is it important to use ripe bana for DNA extraction?
Unripe bananas have tough cell walls
for the organic RNA isolation, ___ is a strong denaturant of RNases and can be used instead of high-salt buffers
guanidium isothiocyanate
After adding precipitation agent in a mashed banana the extracted nucleic acid will
float/clump
separation technique of molecules & ions performed in a narrow capillary tube structure using electric current
capillary electrophoresis
for differential density gradient centrifugation, whole blood or bone marrow mixed with ___ is overlaid with ficoll
isotonic saline
this chemical is commonly used as a detergent in DNA extraction to break down cell membranes
sodium dodecyl sulfate
under organic isolation method, the excess salt in DNA precipitation is removed by rinsing the pelleted nucleic acid in what concentration of ethanol?
70%
mitochondrial DNA can then be precipitated with
cold ethanol
the ratio of absorption at 260 nm to absorption at 280 nm is commonly uses to assess
the purity of DNA and RNA with respect to protein
these sources of circulating nucleic acids can be detected for purposes of diagnostic and prognostic analyses, uch as liquid biopsy
exosomes
antigenic sites on the protein
epitopes
what 2 fixative yields good quality of DNA and RNA
Acetone
10% neutral buffered formalin
probe folding is a strong in sequences with high ____
GC
luminol, as a detection system label may emit ___ light
blue
the equivalent of path length i
1CM
what solution is used to deparaffinized frozen tissue?
xylene
after exposing to your answer in number 3 what is used to rehydrate the frozen tissue?
ethanol
the cell membrane of a gram negative bacteria is lysed by?
alkaline (high ph)
what method uses spin column or beads?
solid-phase method
removal of nucleic acids (DNA and/or
RNA) from the cells in which they normally reside
Nucleic Acid Extraction
free from contamination with macromolecules such as: proteins, carbohydrates, lipids, or
other nucleic acids
Target nucleic acids
How Nucleic Acid is Removed from the Cell?
- Bust out the cell membrane
- Lysis of cell wall or cell membrane
- Lysis of nuclear membrane
- Nucleic acids come out from nucleus
- Purification
- Determination of the concentration and purity of the sample
solated the nuclein (DNA) from the WBCs he obtained from the pus on collected surgical bandages in a nearby hospital. (Precipitation
process)
Friedrich Miescher (1869)
demonstrate the
semi-conservative replication of DNA
Meselson & Stahl (1958)
Can be lysed by high pH (alkaline) and detergents
Gramnegative
bacteria
Can be lysed byenzyme products or mechanically grinding or by vigorously mixing
with glass beads (to crack them open and to break down the bonds present)
Some bacteria &
fungi with tough cell
walls
Commercial reagents designed for isolation of DNA in amplification procedures (PCR)
Yeast, filamentous fungi, & grampositive bacteria
LOCATION: archea and bacteria.
➔ FUNCTION: guides a common enzyme to specific sites determined
by RNA components.
➔ USE: manipulation of both DNA sequence and RNA expression
CRISPR Enzyme Systems
target dsDNA
types l and ll
targets ssDNA & RNA
types lll
A reaction that is used to analyze the nucleic acid content of an unknown sample.
➔ Formation of H bonds between 2 complementary strands of nucleic acid.
Hybridization Technologies
➔ ss fragment of nucleic acid/protein
with a detectable signal that specifically binds to complementary sequences/target protein.
➔ PURPOSE: identify one or more sequences of interest with a large amount of nucleic acids.
➔ OTHER USED: modified nucleic acid,
such as peptide nucleic acids and locked nucleic acids.
PROBE
IN ORDER THE PROBE TO BIND
target nucleic acid has
to contain the sequence of interest.
DENATURATION OF dsDNA PROBED BEFORE USE:
● Heating the probe (95
degree celsius, 10-15 minutes) in hybridization solution.
● Treating with 50%
formalin/2x SSC at a
lower temperature for
a shorter time (75
degree celsius, 5-6 minutes).
coding strand transcript.
SOUTHERN BLOT
what solution is used to deparaffinized fixed embedded tissue?
xylene
widely regarded as among the most sensitive method for nucleic acid quantitation
fluorometry
sample is applied to a multi-well chip & then moves through microchannels across a detector
microfluidics
other DNA specific dyes of flourescent spectroscopy
- pico green
- oli green
molar absorptivity of RNA in L/mol-cm
40
molar absorptivity of DNA in L/mol-cm
50
southern blot targets?
DNA
northern blot targets?
RNA
western blot targets?
PROTEIN
