MCDB 428 Exam 1 Questions With
Complete Answers
Size of most tissue culture cells - ANSWER 20-30 um
size of eukaryotic cells - ANSWER 5-100 um
Transmission microscopy - ANSWER white light passed through sample, sample
collected through light piece
epifluorescence microscopy - ANSWER specimen illuminated with light of a
specific wavelength, light absorbed and re-emitted fluorescence is collected
through eyepiece
brightfield microscopy - ANSWER light transmitted through sample, contrast
made by absorption of light in dense areas of specimen
phase-contrast microscopy - ANSWER phase shifts of light converted to
changes in amplitude, which are observed as differences in image contrast
DIC microscopy - ANSWER similar to phase contrast, takes image at an angle to
produce a '3d' image
dark field microscopy - ANSWER unscattered beam of light excluded from image
primary antibody - ANSWER produced in an animal, binds to specific antigen
secondary antibody - ANSWER binds to primary antibody, can contain
fluorescence markers
GFP - ANSWER small protein from aequorea victoria, accepts blue light and
fluoresces green, can be used to tag other cellular proteins and follow
localization
FRAP - ANSWER fluorescence recovery after photobleaching, area
photobleached, diffusion allows certain region to recover fluorescence
FLIP - ANSWER fluorescence loss in photobleaching, photobleach separate
area, analyze fluorescence as it decreases in area of interest to replace
photobleached area
electron microscope resolution - ANSWER 0.1 nm
, super resolution microscope can reach - ANSWER ~30-50 nm
storm microscopy - ANSWER utilizes cycles of activation and bleaching to allow
separated fluorecent molecules to be detected, location of fluorescent molecule
is added to a position on a map, can build a structure through fluoresence
TEM - ANSWER transmission electron microscopy, illuminates samples with high
energy electron wave, high resolution imaging of down to 0.1nm
disadvantages of electron microscopy - ANSWER requires fixed samples (dead
cells)
immuno-gold labelling - ANSWER primary antibody + gold conjugated secondary
antibody can bind to protein of interest, allowing for visualization
scanning electron microscopy - ANSWER collects reflected electrons off the
surface of samples, provides a 3d image
freeze-fracturing - ANSWER SEM can only see surfaces, cell needs to be
cracked open by freeze fracturing, specimen immersed in liquid nitrogen and
pushed against a blade to split the tissue, fractured surfaces etched with heay
metal
monoclonal antibody production - ANSWER mouse immunized with an antigen,
cells make anti-x antibody, b-lymphocytes fused with tumor b-lymphocytes,
making hybridoma cells that can constantly secrete antibody. select clones that
secrete the best antibody can be isolated and grown
velocity sedemntation - ANSWER particles separated by relative size M(r),
combination fo size and density, sucrose or high density liquid used to increase
time for particles to sediment to bottom fo tube, slow sedimenting component on
top, fast sedimenting on bottom
differential centrifugation - ANSWER lower speed pellet contains cells, nuclei,
cytoskeletons
meidum speed contains mitochondria, lysosome, peroxisomes
high speed contains microsomes, small vesicles
very high speed contains ribosomes, viruses, large macromolecules
equilibrium gradient - ANSWER organelles of different densities separated
based on density, presence of distinct protein composition increases density,
proteins are denser, lipids are lighter
sds page - ANSWER sds denatures proteins and negatively charges proteins,
run on gel to show size of protein
Complete Answers
Size of most tissue culture cells - ANSWER 20-30 um
size of eukaryotic cells - ANSWER 5-100 um
Transmission microscopy - ANSWER white light passed through sample, sample
collected through light piece
epifluorescence microscopy - ANSWER specimen illuminated with light of a
specific wavelength, light absorbed and re-emitted fluorescence is collected
through eyepiece
brightfield microscopy - ANSWER light transmitted through sample, contrast
made by absorption of light in dense areas of specimen
phase-contrast microscopy - ANSWER phase shifts of light converted to
changes in amplitude, which are observed as differences in image contrast
DIC microscopy - ANSWER similar to phase contrast, takes image at an angle to
produce a '3d' image
dark field microscopy - ANSWER unscattered beam of light excluded from image
primary antibody - ANSWER produced in an animal, binds to specific antigen
secondary antibody - ANSWER binds to primary antibody, can contain
fluorescence markers
GFP - ANSWER small protein from aequorea victoria, accepts blue light and
fluoresces green, can be used to tag other cellular proteins and follow
localization
FRAP - ANSWER fluorescence recovery after photobleaching, area
photobleached, diffusion allows certain region to recover fluorescence
FLIP - ANSWER fluorescence loss in photobleaching, photobleach separate
area, analyze fluorescence as it decreases in area of interest to replace
photobleached area
electron microscope resolution - ANSWER 0.1 nm
, super resolution microscope can reach - ANSWER ~30-50 nm
storm microscopy - ANSWER utilizes cycles of activation and bleaching to allow
separated fluorecent molecules to be detected, location of fluorescent molecule
is added to a position on a map, can build a structure through fluoresence
TEM - ANSWER transmission electron microscopy, illuminates samples with high
energy electron wave, high resolution imaging of down to 0.1nm
disadvantages of electron microscopy - ANSWER requires fixed samples (dead
cells)
immuno-gold labelling - ANSWER primary antibody + gold conjugated secondary
antibody can bind to protein of interest, allowing for visualization
scanning electron microscopy - ANSWER collects reflected electrons off the
surface of samples, provides a 3d image
freeze-fracturing - ANSWER SEM can only see surfaces, cell needs to be
cracked open by freeze fracturing, specimen immersed in liquid nitrogen and
pushed against a blade to split the tissue, fractured surfaces etched with heay
metal
monoclonal antibody production - ANSWER mouse immunized with an antigen,
cells make anti-x antibody, b-lymphocytes fused with tumor b-lymphocytes,
making hybridoma cells that can constantly secrete antibody. select clones that
secrete the best antibody can be isolated and grown
velocity sedemntation - ANSWER particles separated by relative size M(r),
combination fo size and density, sucrose or high density liquid used to increase
time for particles to sediment to bottom fo tube, slow sedimenting component on
top, fast sedimenting on bottom
differential centrifugation - ANSWER lower speed pellet contains cells, nuclei,
cytoskeletons
meidum speed contains mitochondria, lysosome, peroxisomes
high speed contains microsomes, small vesicles
very high speed contains ribosomes, viruses, large macromolecules
equilibrium gradient - ANSWER organelles of different densities separated
based on density, presence of distinct protein composition increases density,
proteins are denser, lipids are lighter
sds page - ANSWER sds denatures proteins and negatively charges proteins,
run on gel to show size of protein
