SCYM (ASCP) EXAM (2026) ACTUAL EXAM
COMPREHENSIVE QUESTIONS AND VERIFIED
ACCURATE SOLUTION (DETAILED &
ELABORATED) |GET IT 100% ACCURATE!! 2026
TEST!!
Terms in this set (133)
Hydrodynamic Focusing Most modern flow cytometers tightly position the
sample for optical analysis via hydrodynamic
focusing. Here, a carrier fluid called the sheath
fluid is used to position the sample of cells into a
single file for optical interrogation.
Hydordynamic focusing and sheath The central stream (sample stream) is focused and
fluids surrounded by the secondary slower stream
(sheath fluid). The shape and size of the flow cell is
crucial to hydrodynamic focusing, and traditionally
the cell is nozzle shaped. ... In a flow cytometer,
the sheath fluid pressure is constant while the
sample fluid is adjusted
Sample Pressure and the Sheath The difference between the sample pressure and
Pressure the sheath pressure is the differential pressure. This
controls the width of the core stream and the total
number of cells passing the laser intercept.
,differential pressure based flow Differential pressure based flow cytometers
cytometers currently dominate the market. These systems have
two pressure regulators. The first is at a constant
pressure that sets how fast the fluids runs at. The
second is regulated by the investigator (like on this
LSR-II control panel).
Generation of differential pressure Low differential pressure allows the cells to move
(syringe pump, pressure based) past the interrogation point one at a time. .... One
kind involves generating pressure using a pump
and regulator system ... Differential pressure based
fluidic system. ... peristaltic and/or syringe pumps
to deliver the sample into the instrument.
Characterization of syringe-pump- In syringe-pump-driven microfluidic systems,
driven induced pressure pressure fluctuations are observed in an elastic
microchannel. The syringe pump is driven by an
electrical stepper motor, from which mechanical
oscillations are expected to generate flow-rate
fluctuations and in turn leads to the pressure
fluctuations in the channel flow.
Optical Filters Filters are pieces of glass coated on both sides that
allow light of a certain collection, or band, of
wavelengths to pass through while absorbing or
interfering with photons of other wavelengths.
These come in bandpass, longpass, and shortpass
flavors
Band Pass Optical Filter A filter that allows light between a set wavelength
to pass through and reflects light above and below
the set wavelength. For example, a bandpass filter
with a wavelength of 550/40nm would allow light
between 530nm and 570nm to pass through, but
reflect light below 530nm and above 570nm.
,Longpass Filter wavelength above 650nM
Shortpass Filter wavelength below 488nM
dichroics mirrors Dichroic mirrors can block light by phased
reflection allowing certain light to pass through
and interfering with other wavelengths. For
example, a 500LP dichroic mirror would transmit
light above 500 nm and reflect the light below 500
nm in a different direction. A 525SP dichroic mirror
would transmit all light below 525 nm and reflect
all light above 525 nm in a different direction. These
dichroic mirrors are critical in the directing and
capturing of light by the detectors.
neutral density filter filter that reduces or modifies the intensity of all
wavelengths, or colors, of light equally, giving no
changes in hue of color rendition
polarization filter Polarization of scatter and fluorescence signals in
flow cytometry. ... depending on the light source(s),
the optical layout, and the types of mirrors and
filters used.
light source The light source can be a laser, an arc lamp or even
an LED. Today, the majority of instruments use a
laser. Lasers illuminate the stream with coherent,
focused light of specific wavelength (energy) and
power. This illumination facilitates the generation of
fluorescence signals from cells labeled with
fluorophores and light scatter signals from
redirected laser light.
, arc lamp laser Arc lamps need optical filters to select the
appropriate wavelength. They do not give the
sensitivity needed to observe weak fluorescence
but offer a cheaper alternative for observing
strong fluorescences, for example, in DNA analysis.
argon laser Air-cooled argon-ion laser producing blue light at
488 nm. This wavelength is convenient for the
excitation of fluorescein, the first
immunofluorescent label to be used. Other air-
cooled lasers in general use include He-Ne (633
nm) and He-CD (325 nm).
solid state lasers Solid state lasers producing light at 355, 405, 488,
530, 594, 635 and 780 nm are available. Most solid
state lasers produce between 10 and 25 mW. There
is at least one diode laser giving 200 mW at 488
nm.
lenses As the lasers interact with particles and cells at the
observation point or the interrogation point,
scattered and fluorescence light is generated. In
order to measure this light, the cytometer needs to
collect as much of it as possible.
What is the job of the lenses? The optical collection system of a cytometer must
accomplish two goals. First, it must gather as much
light as possible from the interrogation point.
Second, it must collimate that light so that all rays
propagate parallel to each other and can travel
through the collection path without diverging.
COMPREHENSIVE QUESTIONS AND VERIFIED
ACCURATE SOLUTION (DETAILED &
ELABORATED) |GET IT 100% ACCURATE!! 2026
TEST!!
Terms in this set (133)
Hydrodynamic Focusing Most modern flow cytometers tightly position the
sample for optical analysis via hydrodynamic
focusing. Here, a carrier fluid called the sheath
fluid is used to position the sample of cells into a
single file for optical interrogation.
Hydordynamic focusing and sheath The central stream (sample stream) is focused and
fluids surrounded by the secondary slower stream
(sheath fluid). The shape and size of the flow cell is
crucial to hydrodynamic focusing, and traditionally
the cell is nozzle shaped. ... In a flow cytometer,
the sheath fluid pressure is constant while the
sample fluid is adjusted
Sample Pressure and the Sheath The difference between the sample pressure and
Pressure the sheath pressure is the differential pressure. This
controls the width of the core stream and the total
number of cells passing the laser intercept.
,differential pressure based flow Differential pressure based flow cytometers
cytometers currently dominate the market. These systems have
two pressure regulators. The first is at a constant
pressure that sets how fast the fluids runs at. The
second is regulated by the investigator (like on this
LSR-II control panel).
Generation of differential pressure Low differential pressure allows the cells to move
(syringe pump, pressure based) past the interrogation point one at a time. .... One
kind involves generating pressure using a pump
and regulator system ... Differential pressure based
fluidic system. ... peristaltic and/or syringe pumps
to deliver the sample into the instrument.
Characterization of syringe-pump- In syringe-pump-driven microfluidic systems,
driven induced pressure pressure fluctuations are observed in an elastic
microchannel. The syringe pump is driven by an
electrical stepper motor, from which mechanical
oscillations are expected to generate flow-rate
fluctuations and in turn leads to the pressure
fluctuations in the channel flow.
Optical Filters Filters are pieces of glass coated on both sides that
allow light of a certain collection, or band, of
wavelengths to pass through while absorbing or
interfering with photons of other wavelengths.
These come in bandpass, longpass, and shortpass
flavors
Band Pass Optical Filter A filter that allows light between a set wavelength
to pass through and reflects light above and below
the set wavelength. For example, a bandpass filter
with a wavelength of 550/40nm would allow light
between 530nm and 570nm to pass through, but
reflect light below 530nm and above 570nm.
,Longpass Filter wavelength above 650nM
Shortpass Filter wavelength below 488nM
dichroics mirrors Dichroic mirrors can block light by phased
reflection allowing certain light to pass through
and interfering with other wavelengths. For
example, a 500LP dichroic mirror would transmit
light above 500 nm and reflect the light below 500
nm in a different direction. A 525SP dichroic mirror
would transmit all light below 525 nm and reflect
all light above 525 nm in a different direction. These
dichroic mirrors are critical in the directing and
capturing of light by the detectors.
neutral density filter filter that reduces or modifies the intensity of all
wavelengths, or colors, of light equally, giving no
changes in hue of color rendition
polarization filter Polarization of scatter and fluorescence signals in
flow cytometry. ... depending on the light source(s),
the optical layout, and the types of mirrors and
filters used.
light source The light source can be a laser, an arc lamp or even
an LED. Today, the majority of instruments use a
laser. Lasers illuminate the stream with coherent,
focused light of specific wavelength (energy) and
power. This illumination facilitates the generation of
fluorescence signals from cells labeled with
fluorophores and light scatter signals from
redirected laser light.
, arc lamp laser Arc lamps need optical filters to select the
appropriate wavelength. They do not give the
sensitivity needed to observe weak fluorescence
but offer a cheaper alternative for observing
strong fluorescences, for example, in DNA analysis.
argon laser Air-cooled argon-ion laser producing blue light at
488 nm. This wavelength is convenient for the
excitation of fluorescein, the first
immunofluorescent label to be used. Other air-
cooled lasers in general use include He-Ne (633
nm) and He-CD (325 nm).
solid state lasers Solid state lasers producing light at 355, 405, 488,
530, 594, 635 and 780 nm are available. Most solid
state lasers produce between 10 and 25 mW. There
is at least one diode laser giving 200 mW at 488
nm.
lenses As the lasers interact with particles and cells at the
observation point or the interrogation point,
scattered and fluorescence light is generated. In
order to measure this light, the cytometer needs to
collect as much of it as possible.
What is the job of the lenses? The optical collection system of a cytometer must
accomplish two goals. First, it must gather as much
light as possible from the interrogation point.
Second, it must collimate that light so that all rays
propagate parallel to each other and can travel
through the collection path without diverging.
