SCYM (ASCP) Study Guide Exam.
1. Hydrodynam
Most modern flow cytometers tightly position the sample for optical analys
ic Focusing
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
2. Hydordynam interrogation.
ic focusing
The central stream (sample stream) is focused and surrounded by the
and sheath
secondary slower stream (sheath fluid). The shape and size of the flow
fluids
cell is crucial to hydrodynamic focusing, and traditionally the cell is
nozzle shaped.................................................................In a flow
3. Sample cytometer, the sheath fluid pressure is constant while the sample fluid is
adjusted
Pressure and
the Sheath The ditterence between the sample pressure and the sheath
Pressure pressure is the ditterential pressure. This controls the width of the
core stream and the total number of cells passing the laser
4. differential
intercept.
pres- sure
based flow Ditterential pressure based flow cytometers currently dominate the market.
cytometers 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).
5. Generation of dif- Low ditterential pressure allows the cells to move past the interrogation
point one
ferential pres- ringe-pump-dri- ven induced pressure
sure (syringe
pump,
pressure
based)
6. Characterizatio
n of
sy-
, SCYM (ASCP) Study Guide Exam.
time............One kind involves
generating pressure using a
pump and regulator In syringe-pump-driven microfluidic systems, pressure fluctuations are
em ... Ditterential pressure observed in an elastic microchannel. The syringe pump is driven by an
based fluidic system........................................
electrical stepper motor, from which mechanical oscillations are
peristaltic and/or syringe
expected to generate flow-rate fluctuations and in turn leads to the
ps to deliver the sample into
pressure fluctuations in the channel flow.
the instrument.
7. Optical Filters Filters are pieces of glass coated on both sides that allow light of a certai
collection, or band, of wavelengths to pass through while absorbing or
interfering
, SCYM (ASCP) Study Guide Exam.
with photons of other wavelengths. These come in bandpass, longpass,
and shortpass flavors
8. Band Pass A filter that allows light between a set wavelength to pass through and
Opti- cal Filter 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.
9. Longpass Filter wavelength above 650nM
10. Shortpass Filter wavelength below 488nM
11. 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 ditterent direction. A 525SP
dichroic mirror would transmit all light below 525 nm and reflect all light
above 525 nm in a ditterent direction. These dichroic mirrors are critical
in the directing and capturing of light by the detectors.
12. neutral filter that reduces or modifies the intensity of all wavelengths, or colors, of ligh
density filter equally, giving no changes in hue of color rendition
13. 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.
14. 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
, SCYM (ASCP) Study Guide Exam.
fluorophores and light scatter signals from redirected laser light.
15. arc lamp laser Arc lamps need optical filters to select the appropriate wavelength. They d
not
give the sensitivity needed to observe weak fluorescence but otter a
cheaper alternative for observing strong fluorescences, for example, in
DNA analysis.
1. Hydrodynam
Most modern flow cytometers tightly position the sample for optical analys
ic Focusing
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
2. Hydordynam interrogation.
ic focusing
The central stream (sample stream) is focused and surrounded by the
and sheath
secondary slower stream (sheath fluid). The shape and size of the flow
fluids
cell is crucial to hydrodynamic focusing, and traditionally the cell is
nozzle shaped.................................................................In a flow
3. Sample cytometer, the sheath fluid pressure is constant while the sample fluid is
adjusted
Pressure and
the Sheath The ditterence between the sample pressure and the sheath
Pressure pressure is the ditterential pressure. This controls the width of the
core stream and the total number of cells passing the laser
4. differential
intercept.
pres- sure
based flow Ditterential pressure based flow cytometers currently dominate the market.
cytometers 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).
5. Generation of dif- Low ditterential pressure allows the cells to move past the interrogation
point one
ferential pres- ringe-pump-dri- ven induced pressure
sure (syringe
pump,
pressure
based)
6. Characterizatio
n of
sy-
, SCYM (ASCP) Study Guide Exam.
time............One kind involves
generating pressure using a
pump and regulator In syringe-pump-driven microfluidic systems, pressure fluctuations are
em ... Ditterential pressure observed in an elastic microchannel. The syringe pump is driven by an
based fluidic system........................................
electrical stepper motor, from which mechanical oscillations are
peristaltic and/or syringe
expected to generate flow-rate fluctuations and in turn leads to the
ps to deliver the sample into
pressure fluctuations in the channel flow.
the instrument.
7. Optical Filters Filters are pieces of glass coated on both sides that allow light of a certai
collection, or band, of wavelengths to pass through while absorbing or
interfering
, SCYM (ASCP) Study Guide Exam.
with photons of other wavelengths. These come in bandpass, longpass,
and shortpass flavors
8. Band Pass A filter that allows light between a set wavelength to pass through and
Opti- cal Filter 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.
9. Longpass Filter wavelength above 650nM
10. Shortpass Filter wavelength below 488nM
11. 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 ditterent direction. A 525SP
dichroic mirror would transmit all light below 525 nm and reflect all light
above 525 nm in a ditterent direction. These dichroic mirrors are critical
in the directing and capturing of light by the detectors.
12. neutral filter that reduces or modifies the intensity of all wavelengths, or colors, of ligh
density filter equally, giving no changes in hue of color rendition
13. 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.
14. 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
, SCYM (ASCP) Study Guide Exam.
fluorophores and light scatter signals from redirected laser light.
15. arc lamp laser Arc lamps need optical filters to select the appropriate wavelength. They d
not
give the sensitivity needed to observe weak fluorescence but otter a
cheaper alternative for observing strong fluorescences, for example, in
DNA analysis.
