Order in the blood bank: automation steps up
October 2002 William Check, PhD
When David Wenham began working in blood banking more than
30 years ago, syphilis was the only infectious disease tested for. "I have
seen a lot of changes since that time," says Wenham, who is a Fellow of
the Institute of Biomedical Sciences and manager of processing, testing, and
issue operations at the National Blood Service, Colindale Center (North London).
Advances have come particularly in automated equipment, Wenham says. "In
the early ’70s, we added testing for hepatitis B virus. It was purely manual
at first. Then we moved to microtiter-based hemagglutination systems, on to
RIAs, then to ELISAs." Microtiter-based EIAs appeared in the mid-’80s.
Automation proceeded from plate readers to robotic sample processors, then gradually
in the early ’90s to automated microplate processing. An ocean and a continent
away, at the UCLA Medical Center, Loni Calhoun, MT(ASCP) SBB, senior technical
specialist in the Division of Transfusion Medicine, describes a similar situation
in antibody screening. Initially, it was done by a tube method. However, Calhoun
says, "Our workload was growing and we couldn’t get more technologists.
So we wanted a system we could automate."
Demand for automation is keen across all clinical laboratory fields. But it
is particularly intense in blood banking. "Blood banking is one of the
last bastions of true piecework in laboratory medicine," says Edward Lipford,
MD, pathologist and medical director, Carolinas Laboratory Network. "We
need to do anything we can to move blood banking into the current era of automation
and greater efficiency while keeping the same highly specific patient results."
Dr. Lipford’s colleague, Jared Block, MD, medical director of the transfusion
service of the Carolinas Laboratory Network and at Carolinas Medical Center
in Charlotte, recently made site visits to look at new automated systems. "The
justification I heard from many places was FTE savings," Dr. Block says.
"We were down two FTEs. Other places were down many more."
Pressure for automation also derives from the greater number of bloodborne infectious
diseases. In addition to a serologic test for Treponema pallidum, in
the United States donor blood must be screened for the surface antigen of hepatitis
B virus as well as for antibodies to HBV core, hepatitis C virus, HIV types
1 and 2, and human T cell lymphotropic virus types I and II. Also mandatory
are tests for HCV and HIV RNA. Antibodies to cytomegalovirus may be sought in
selected cases. And at its Sept. 12 meeting, the FDA’s Blood Products
Advisory Committee discussed adding tests for Chagas disease and West Nile virus.
One consequence of the drive to automation is described by Steve Negin, MT(ASCP)SBB,
laboratory manager at the Central California Blood Center in Fresno. "It
is getting to be almost impossible for small or even medium-sized donor centers
to be cost-effective," Negin says. "Small centers are just not going
to be able to afford automation. We have already started to see, as inspectors
see more automated systems, they are asking smaller non-automated centers, ’How
are you capturing the additional information that the automated system is capturing?’
Without automation, that is next to impossible."
Negin details some QC steps performed by the instrument that he uses to test
for viral markers. In manual testing, the temperature of a reaction would be
taken when putting in a plate and when taking it out. "This system continually
monitors temperature in each slot," he says, "and it will lock out
a slot if there is a problem." Moreover, the instrument profiles intermediate
steps that weren’t even monitored before, such as exact wash times and times
to add reagents, within seconds.
German Leparc, MD, chief medical officer of Florida Blood Services, St. Petersburg,
agrees that automation provides benefits beyond staffing reduction. "Perhaps
the biggest impact of automation has been in allowing us to meet current GMP
requirements," Dr. Leparc says. "Such things as incubation times and
other processing steps that before needed to be documented by hand are now done
by the instrument. If limits are exceeded, the instrument will invalidate those
results." No longer must technologists exhaustively review sample records
when a problem is detected after a run.
Automated or semiautomated instruments are available for the two main blood
bank functions—determining blood type and screening for antibodies (type
and screen), and assaying for infectious diseases.
Type and screen
Newer automated or semiautomated instruments that type and screen
timized for either donor collection settings (Immucor Rosys Plato)
or patient transfusion settings (Immucor ABS 2000, Ortho Tecan MegaFlex).
One exception is the Olympus Tango, which adapts to either setting
but is available now only in Europe.
At Massachusetts General Hospital, Sunny Dzik, MD, co-director of
the blood transfusion service, oversees testing of about 39,000
units of blood annually, either collected from donors or purchased
from the Red Cross. "We use the Rosys principally to do a basic
type and two-cell screen on blood donated at MGH," Dr. Dzik
says. (Patient antibody screening is done on gel cards using a three-cell
screen.) The Rosys can also perform syphilis screening and CMV serologic
testing.
Dr. Dzik says the Rosys processes 94 samples per run and takes 1.5
hours to do the basic required set of tests. "It is definitely
not a walkaway instrument," he says. For instance, a technologist
is involved in physically transferring microtiter plates to a reader
at a particular time. However, Dr. Dzik says, "I don’t see
that as a major disadvantage."
In the Carolinas Laboratory Network, which services four hospitals
in Mecklenburg County, the transfusion service transfuses about
35,000 units per year. They use both a Rosys and an ABS 2000 to
perform type and screens. "These instruments allow us to do
our work in large batches without using as much manpower,"
Dr. Block says. The Rosys does a two-cell screen, the ABS a four-cell
screen. Says Barbara McElhiney, manager of transfusion services:
"We do both donor and patient type and screens on the Rosys.
The ABS 2000 is used primarily for patient type and screens, but
it could be used for donor testing also."
In practice, Dr. Block explains, "We separate our workload.
We do the majority of our work on the Rosys, which has higher throughput,
while the ABS allows us to separate out smaller batches." Samples
from obstetrical patients and trauma or surgical patients who are
not bleeding heavily might be batched. A type and crossmatch used
to take 45 minutes. "Now," Dr. Block says, "we can
do four in under an hour, and they all come out at the same time."
He estimates that the instruments have saved 3.5 FTEs: "We
were down two FTEs and the instruments allowed us to reduce staff
by another 1.5 through attrition."
Dr. Block finds the instruments’ sensitivity to be good. "We
have picked up some significant antibodies like anti-E and anti-Kell
that we would not have picked up manually," he says. Antibodies
were verified with sensitive manual techniques.
When they were evaluating the Ortho gel system, they were told that
the solid-phase technology (Immucor) would produce a problematic
level of false-positives. "Before purchasing the system,"
Dr. Block says, "we evaluated the presentation data prepared
by an advocate of gel. We examined the data used to conclude that
gel renders fewer false-positive results, and the data appeared
to be flawed." The initial review found that the data sets
were obtained from two separate populations of samples. Therefore,
Dr. Block says, "the comparison was not truly apples to apples."
In addition, he says, the results within the studies on the gel
system suggest that "significant antibodies were missed by
this method—21 anti-E, seven Kidd, seven Kell, all picked
up with PEG and not by gel." Dr. Block’s laboratory has seen
about three false-positive results per month since it implemented
the Immucor system in April of this year. "This is from an
approximate sample size of 1,800 per month," he says.
The Immucor alternative had advantages. "The Ortho proposal
placed a single instrument here, whereas the Immucor proposal placed
both the Rosys and the smaller instrument," Dr. Lipford says.
"That gave us what we thought was greater flexibility and some
core redundancy in our automated blood banking operation for approximately
the same initial capitalization."
Reagent cost was also a consideration, says Dr. Block, who recalls
the Ortho system reagents as being far more expensive. "It
actually amounted to a recurring reagent cost of $100,000 per year
greater, even though the capital outlay was the same," Dr.
Block says.
Another major factor, in Dr. Lipford’s view, was that the Immucor
instruments are truly bar-coded, with an on-instrument bar-code
reader. "Whereas the current version of the Ortho instrument
reads the bar code first, then the instrument remembers its rack
position. Since that is not direct tube reading, there is always
a potential for error if you put the tube in the wrong place,"
Dr. Lipford notes.
Other institutions selected an Ortho instrument. In 1995, the transfusion
service at Emory University Hospital, which transfuses 18,000 red
cell units per year, moved from manual tube testing to a manual
gel system, says Mary Beth Allen, MS, MT(ASCP), administrative director
of laboratories. In 1998 they moved to full automation. "We
do typing for patients and donors, antibody screens, and donor type
confirmation," Allen says. "But our transfusion service
is most important.
"We evaluated across the market," she continues, "including
both Immucor and Ortho instruments." They purchased an Ortho
Tecan MegaFlex. "It automates the entire pipetting process,"
Allen says. It also includes automated centrifuging and reading.
Since Emory is a tertiary care hospital, many patients have been
transfused previously. "Typically we see 10 to 15 percent of
patients with antibodies," Allen says. "With the Tecan
we very rarely see a false-positive. With other systems we have
seen some false-positive results."
The decision to go with automation at that particular time was driven
entirely by staff reduction issues, Allen says: "Our staff
was already reducing despite our best efforts." When they were
doing manual tube testing, they had six FTEs on the day shift to
do routine serological testing. When they moved to manual gels,
it went down to two. Now only one person is required.
Allen is not disturbed that the Tecan is not a true walkaway, requiring
an operator to transfer the gel card at various steps. "I don’t
know that there is a true walkaway yet in the U.S.," she says.
"Several are under development and may be available in Europe.
But it can be a challenge to get these instruments through FDA;
it’s a fairly rigorous process."
Allen’s advice: "Any facility that is considering moving to
automation—which I heartily recommend—should evaluate
everything on the market based on their specific facility."
At UCLA Medical Center, Calhoun helps oversee
technical operations in the transfusion service, which uses about
34,000 red blood cell products a year. They, too, chose the Ortho
Tecan MegaFlex system to automate patient type and screens. Calling
the MegaFlex their "workhorse," Calhoun says, "We
tell it what tests we want to run on how many specimens; the instrument
tells us what reagents and gel cards to add and where." Program
prompts are easy to follow. "We load the specimens. It prepares
cell suspensions, pipettes the cells and plasma, and tracks the
identity of every test on every card by bar code," she says.
Because the specimen bar code is not read until the sample is pipetted,
incoming stats are easy to add—they simply substitute the
next specimen to be bar-coded with the stat specimen. A batch of
24 specimens can be completed easily in an hour.
Although test cards must be manually moved for incubation and centrifugation,
a companion centrifuge-reader simplifies result entry. The MTS Reader
SA instrument centrifuges and reads up to 24 cards at one time.
A picture of each card’s results, with strength of reactivity and
result interpretation, is displayed on a computer screen. A technologist
reviews the display and accepts or changes the data as needed, then
exports the data to the LIS. "Because many of our patients
have serologic discrepancies, we have chosen not to export interpretations
at this time," Calhoun says. "A technologist reviews results
in the laboratory computer for final interpretation."
Calhoun likes the Tecan system’s versatility. It can be set up to
screen for or crossmatch donor units of specific phenotypes, such
as when a patient needs E, c-negative blood. "We can use the
pipetting instrument and reader for many test applications, as long
as we properly validate them for that use," she says.
When making its choice, UCLA compared the Ortho gel and Immucor
solid-phase methodologies in a parallel trial of 300 specimens.
"Our primary selection criterion," Calhoun says, "was
which method worked better in our setting." They were able
to detect more clinically significant antibodies with gel than with
solid phase. "Although solid phase was more sensitive, with
our patient population it also detected many more autoantibodies
of dubious significance, and these obscured the underlying alloantibodies
we clearly detected with gel," she says. Gel reactions were
consistently stronger than LISS-IgG tube reactions. Moreover, technologists
participating in the trial study preferred the gel system and found
it easier to adapt to.
Since implementing the Tecan, staff size has not changed, Calhoun
says, but workload has increased and become more complex. "Automation
has allowed us to re-engineer job tasks and use staff more efficiently.
Plus we have a testing system in place that is objective, reliable,
and reduces the risk of clerical error. Automation has saved us,"
she says.
The Olympus Tango, which is not available now in the U.S.,
promises even further advantages. (Biotest AG is the manufacturer of the Tango and associated
reagents and distributes directly in Europe. In North America, Olympus
will be the distributor.) While it can be difficult to compare instruments
that have not been cleared by the FDA with those that have, interviews with laboratorians
in the United Kingdom who are using this instrument suggest that
it is accurate, flexible, and fully automated.
Queens Medical Centre, Nottingham, is a large acute-care teaching
hospital with a transfusion service that performs about 30,000 blood
groups per year and transfuses about 18,000 units of RBCs. "We
do a full blood group and three-cell antibody screen," says
Linda Hoyland, MSc, chief biomedical scientist and manager of the
transfusion department. "This work is now totally automated
on the Tango." She calls the instrument "a completely
walkaway analyzer—you put the samples on, push a button, and
get results."
In the summer of 1999, Hoyland and her colleagues compared four
analyzers: Tango, DiaMed Diana gel station, Ortho CD Autoview, and
Immucor ABS 2000. "We compared them on sample throughput, technologists
employed, amount of skill needed, whether they were true walkaway,
availability of 24-hour service, and serological performance,"
she says. Ultimately they chose the Tango.
The Tango’s variable throughput was an important factor. It can
work in batch mode, with a capacity of 120 samples. In normal operation
it takes 35 to 40 minutes to get results, according to Hoyland.
But, she says, it is flexible and designed to be able to "trickle
feed"—to add samples singly. For one sample, groups and
screens take 35 minutes; eight samples take 40 minutes. "That
is one of the things that helped us decide," she says. "Others
claim you can put on one sample at a time, but may have restrictions.
With some instruments, if you start a batch before the prior batch
is finished, you can lose some of the earlier results."
She also likes the Tango’s serological performance. "I can’t
fault it," she says. Its edit rate—results that the analyzer
can’t interpret—is about four percent. "In practice,
the actual number of samples that we have to work on manually is less than two percent," Hoyland says. She calls
accuracy for antibody screening "very good." The false-positive
rate is less than one percent.
No false-negative results have yet been recognized. In some patients
whose historical records show an antibody three to four years ago,
the machine did not detect it. But in these cases the antibody wasn’t
confimed by sensitive manual testing either.
The Tango can do crossmatching, Hoyland says, and she plans to implement
it when time allows.
In the Haematology and Blood Transfusion Department at Southampton
General Hospital, a comparative evaluation also led to selection
of the Tango, says laboratory manager Steve Yates, Fellow of the
Institute of Biomedical Sciences. This service provides blood for
hospital patients, performing 60,000 group and screens annually.
In the mid-’90s, the service had a semiautomated liquid-handling
device that used microplate technology, but it had several limitations.
"We needed someone looking after the machine or around it most
of the time," Yates says. "We also felt unhappy about
quality aspects of that device." Results varied with operator
skill. Also, it could be used only for batch analysis, the minimum
batch was 24 samples, and it was unsuitable for 24-hour use at their
staffing level.
They compared approximately the same four instruments that Hoyland
compared. How well each instrument performed serology was the key
consideration. Having all processing done by the instrument itself
was also important. "The Tango fit our needs best," Yates
says. "It was the most sophisticated instrument on the market
at that time," the end of 1999. "It still looks good today."
Serological performance is good. Yates estimates the false-positive
rate for antibodies at less than 0.01 percent. For sensitivity,
he says, "with serology that is always a fuzzy concept. We
now regularly detect clinically significant antibodies that we cannot
detect by a manual column agglutination technique." In the
first six months of this year, the Tango detected the following
antibody specificities that could not be detected by a standard
antiglobulin technique and required enzyme-treated cells for verification:
anti-D-14, anti-Jka-3, anti-Jkb-1, anti-c-1, anti-e-1, and anti-K-1.
Because the Tango is a true walkaway analyzer, the only substantive
technologist time is loading of reagents, which tends to happen
throughout the day. "We have gained at least one staff person,"
Yates says, noting that the lab was automated before Tango was introduced.
Tango’s microplate strip format has eight wells, which allows two
anti-Ds, a true reagent control, and a check of reverse group. With
the column resolution technique, there was a card with six wells
for either antigen or plasma testing. "We felt that was too
few to perform a safe group," Yates says, "because it
allows only one well containing anti-D, no true reagent control,
and no check of reverse group."
Olympus is in the process of scheduling a meeting with the FDA to
review regulatory strategy and field trial protocols and hopes to
start field trials late this year.
Also in Europe, Immucor is marketing a new automated system called
Galileo. It is a fully automated, high-throughput, random-access
blood bank system that performs patient and donor type and Rh, weak
D testing, antibody screening (pooled cell, two-cell, and four-cell),
antibody identification, CMV detection, syphilis detection, and
crossmatching. Immucor is preparing for clinical trials in the United
States.
Donor infectious disease testing
The Ortho Summit System, or OSS, and the Abbott Prism perform infectious
disease tests of donor blood. Abbott’s Prism was FDA cleared in
1999, but the Prism assay approvals have been delayed because of
the FDA’s compliance hold on Abbott’s manufacturing facilities.
At Florida Blood Services, Dr. Leparc says, "We do donor screening
for ourselves as well as for other blood centers." Their annual
workload adds up to almost half a million units. (They do just nucleic
acid testing on another 500,000 units.)
Dr. Leparc’s test menu shows the variety of instruments that a large
blood center must have. For blood typing and syphilis testing, they
use an older instrument, an Olympus PK7200. They use another older,
semiautomated instrument, the Immucor Dias system, to do antibody
screens on blood donors. For HCV and HIV nucleic acid testing, they use Chiron/Gen-Probe FDA-licensed
kits, which are based on transcription-mediated amplification, or
TMA, technology.
For all ELISA testing for transmissible disease markers, they use
the OSS. (Sometimes the Ortho Summit System is referred to as the
Ortho Summit Processor; the Processor is the main component of the
OSS.) The OSS can perform six ID tests for donor screening: HBV
surface antigen and antibodies to HBV core, HCV, HIV, HTLV, and
CMV. Dr. Leparc finds that the OSS has reduced his technologist
requirement for this facet of testing by about 25 percent.
On the transfusion side, which Dr. Leparc calls "one of the
least automated aspects of our operation," he uses the Ortho
manual gel card system for blood typing and antibody screening,
rather than Ortho’s semiautomated Tecan system. "The Tecan
system works well for batching," Dr. Leparc says, "but
it does not give us the fast turnaround times we need for emergencies."
He considers the Immucor ABS 2000 "a fairly good automated
instrument for the transfusion service," but is currently inhibited
by its cost.
Another large blood center, Blood Systems Laboratories in Tempe,
Ariz., has also adopted the OSS for infectious disease testing.
Blood Systems Laboratories (BSL) is a division of Blood Systems
Inc. (BSI) and does donor screening on 1.2 million units per year
for both BSI and several other blood centers and hospitals across
the country. A second BSL donor screening laboratory in Bedford,
Tex., screens an additional 800,000 units.
Gene Robertson, PhD, director of operations for BSL/Tempe, describes
the various systems the facility uses. Like Florida Blood Services,
they use Chiron/Gen-Probe’s semiautomated TMA assay to do nucleic
acid testing for HCV and HIV, and the Olympus PK7200 for blood group
and syphilis testing. For antibody screening, Dr. Robertson uses
the older, semiautomated Immucor Capture-R Ready Screen method.
While he could theoretically transfer these assays to a Rosys, he
says the main issue is throughput capability.
"As far as we understand, the volume we process would not be
practical even on many Rosys systems," Dr. Robertson says.
"We process an average of 3,000 samples per day, up to a maximum
of 6,000."
During the national crisis after Sept. 11, the laboratory was overloaded,
which allowed Dr. Robertson to calculate that the laboratory’s maximum
capacity in a 24-hour period is 8,000 samples.
Donor infectious diesase tests are performed on the Ortho Summit
System. "It is relatively new," Dr. Robertson says. "We
have been on it for over two years. I would still consider it semiautomated,
but it is much more automated than other systems that are available."
The OSS consists of two main instruments: A pipetting system, in which a robotic pipetting arm aspirates samples and dispenses samples and reagents into microplates. A processor that adds reagents to the microplates and incubates, washes, A technologist must first transfer the plates from the pipetting system to the processing system singly as they are prepared. Also,
a technologist must add reagents to the processor or change reagents at certain times during the run as processing moves along. "A
work list generator gives the technologist the tasks, so they have to attend to the system," Dr. Robertson says. "But the
technologist is not performing any critical steps in the assays."
Another advantage is that all steps are documented by the system.
"One of the main benefits we have realized is that the OSS
documents GMP criteria," Dr. Robertson says. "It provides
us with a complete run record."
Microplates have 96 wells, but with various controls each plate
usually processes 88 samples. Calculating throughput or staffing
efficiency in this large facility is complicated. The laboratory
has eight processors and 14 pipetters, with one assay typically being done on each processor and one person
"committed" to each processor. "We have two main
processing shifts," Dr. Robertson says, "because the entire
process cycle time is so long—
approximately 14 hours." Cleanup is done on the first shift.
Within this framework, infectious disease tests on 3,000 to 6,000
samples are done each day.
Overall, Dr. Robertson estimates that the OSS has reduced staffing
requirements for ID testing by about 25 percent.
He has tested the Abbott Prism. "Our laboratory did some clinical
work on it," he says. "That is really a fully automated,
truly walkaway technology. We had a very positive experience with
the system and the results on the assays we performed."
Central California Blood Center in Fresno, with a testing volume
of about 105,000 units per year, is a third large organization that
is doing donor infectious disease testing on the OSS. "We are
an independent blood center serving 30 hospitals in a five-county
area," says laboratory manager Negin. "We also do testing
for two other blood centers and two hospital-based blood centers."
In June 1999, Central California Blood Center became the first blood
center worldwide to go live with all six viral marker tests on the
OSS, Negin says.
He notes that, in addition to the pipetter and processor, the OSS
includes the capability to send raw data back to a built-in server
running a proprietary program, Ortho Assay Software (OAS), which
makes the final calculations on test results and interpretation
and puts out results.
Internal QC features on the OSS score high with Negin—for
example, the continual monitoring of the temperature of incubation
slots and kicking out a plate and locking up a slot when the temperature
goes out of range. "With this approach, you lose one plate
but not the whole run," he says. Also, when dispensing reagents,
the OSS checks to have a certain residual volume in the syringe,
so it can detect mispipetting. "That can be hard to see with
multi-channel pipettes," Negin says.
"And on the new software, if you don’t do weekly or monthly
maintenance, it won’t let you start the machine," he adds.
Negin, like others, finds that automation has allowed him to increase
workload without adding personnel. "On Sept. 1 of this year,
we increased our volume by about 30 to 35 percent with no increase
in FTEs," he says. "With our current configuration we
could probably go to 115,000 to 120,000 samples before we needed
more equipment or more people."
Experience with the Abbott Prism in England suggests that it may further
improve donor infectious disease testing. At the National Blood
Service’s Colindale Center, about 1,000 samples are processed each
day, Wenham says. On the Prism, all donor units are tested for HBV
surface antigen and for antibody to HCV and HIV. About 30 percent
selectively get anti-CMV testing based on donor history. Anti-HTLV
and anti-HBV core are not mandated in the UK. "In the U.S.
you will use all the available channels," Wenham says, "so
it will be even more cost-effective."
He says that the Prism’s advantage is that it is a fully integrated
instrument: It pipettes all samples and reagents, processes plates,
and does plate reading and data interpretation. It also sends data
to a mainframe. "It is a completely closed system," Wenham
says. "There is very little, if any, chance for an operator
at any stage to interfere with either sample processing or plate
processing or reading. So for safety and security, its GMP features
are a long way ahead of open modular systems."
For QC, the Prism performs electronic tracking of samples, keeps
event logs and error messages, and produces proofs of correct processing
of each sample. "It is very cost-effective in terms of staffing,
requiring fewer people than for the equivalent volume through microplate-based
systems," Wenham says.
Throughput is high. Prism produces results for all assays processed
at a rate of 150 samples per hour. Another welcome feature is constant
access, making it possible to add 28-sample racks at any time without
the need for batching. It can also process stat samples.
The Prism is also a walkaway instrument, with one limitation. Because
Wenham’s laboratory routinely processes more samples than the Prism’s
280-sample capacity, a technologist is assigned to load and unload
sample racks. But Wenham doesn’t see this occasional attendance
as a major problem. "We don’t tend to walk away for long periods,"
he says. "There may be things we want to respond to, particularly
the audible alarm that accompanies an error message on the screen."
To run ID tests on 1,000 samples per day, the laboratory has two
Prisms running two shifts (and about 30 percent spare capacity).
On each shift are two junior staff, mostly handling initial sample
preparation, one "qualified" scientist running the instruments,
and a supervisor who primarily oversees the Prism area. "This
represents a reduction of two junior and one qualified person to
perform this testing in comparison to our previous microplate systems,"
Wenham says.
Blood bank directors are optimistic about future improvements. "Automation
in the U.S. is first-generation technology compared to chemistry,"
Allen says. "We are still in our infancy. True walkaway and
random-access instruments will become the norm for blood banking,"
she predicts. "And prices will decline."
Dr. Lipford’s goal for automation is specific and ambitious. "So
far vendors have automated some of the high-volume, highly repetitive
aspects," he says. This includes the ability to run a limited
antibody screen. "What is currently lacking," he says,
"is a good system for antibody identification. That’s something
we would be very interested in having."
William Check is a medical writer in Wilmette, Ill
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