Blastocyst culture selects for euploid embryos: comparison of blastomere and trophectoderm biopsies
Blastocyst culture selects for euploidembryos: comparison of blastomere andtrophectoderm biopsies
Alexis Adler *, Hsaio-Ling Lee, David H McCulloh, Esmeralda Ampeloquio,Melicia Clarke-Williams, Brooke Hodes Wertz, James Grifo
New York University Fertility Center, New York University Langone School of Medicine, 660 1st Ave., 5th Floor, New York,NY 10016, United States* Corresponding author. E-mail address: (A Adler).
Alexis Adler is supervisor of embryology at New York University. Her clinical experience in reproductivemedicine began in 1987 at Cornell, moving to Saint Barnabas before joining NYU in 1995. She consults atprogrammes throughout the USA, China, Taiwan, Israel, Korea, South Africa, and Belgium. Her research inclinical embryology has resulted in abstracts, papers and national and international lectures. Ms Adler receivedher BSc from Barnard College, Columbia University. She has chaired the New York Embryologist Society andASRM's laboratory affiliated society. She also is a member of ACE, Alpha and ESHRE.
genetic diagnosis and screening improves the chances of achieving a viable pregnancy, not only free of
undesired single-gene defects but also aneuploidy. In addition, improvements in vitrification provide an efficient means of preserv-ing embryos (blastocysts). By combining trophectoderm biopsy with recent improvements in vitrification methods, only thoseembryos that have proved themselves viable and potentially more competent are tested. Using array comparative genomic hybrid-ization (aCGH) to assess all 24 chromosomes, aneuploidy rates were compared between day-3 blastomere biopsy and day-5 troph-ectoderm biopsy. Of those 1603 embryos, 31% were euploid, 62% were aneuploid and 7% not analysable. A significantly largerproportion of embryos were euploid on day-5 biopsy (42%) compared with day-3 biopsy (24%, P < 0.0001). The number of euploidembryos per patient was not significantly different. Combining extended culture, trophectoderm biopsy and aneuploidy assessmentby aCGH and subsequent vitrification can provide a more efficient means of achieving euploid pregnancies in IVF. RBM
ª 2014, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
KEYWORDS: aneuploidy, array comparative genomic hybridization, blastomere biopsy, preimplantation genetic screening, trophectodermbiopsy, whole-genome amplification
resulting embryos/fetuses. There are aneuploidies that arepaternal in origin or are post meiotic, occurring after fertil-
A limiting issue in IVF is the age-dependent high incidence of
ization but the majority has been shown originating from
aneuploidy with an abnormal number of chromosomes in the
meiotic nondisjunction in the oocyte ().
1472-6483/ª 2014, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
A Adler et al.
This has been shown to increase with advancing maternal
patients regarding the possible benefits of performing biop-
age ). These untested,
sies only on blastocysts. Recruiting patients to participate in
abnormal embryos, whether transferred or conceived via
this study with cryopreservation and no fresh transfer as
described below was a challenge. Each case was evaluated
(or result in a fetus with an abnor-
and options discussed with patients. Some patients were
mal chromosome compliment often leading to termination.
interested in the variation in treatment options, while oth-
order to screen embryos for euploid status, tradition-
ers were more reticent. Others became aware of the new
ally day-3 cleavage-stage blastomere biopsy is performed
procedure and requested trophectoderm biopsy. Patients
with chromosome analysis of the most common aneuploi-
were enlisted for the study between 1 January 2010 and 1
dies diagnosed by fluorescence in-situ hybridization (FISH).
September 2012. All patients desiring to undergo blasto-
The cells' DNA can also be amplified using PCR to test for
mere biopsy with preimplantation genetic screening for
known single-gene disorders and can provide results in time
aneuploidy determination with or without gender selection
for a day-5 embryo transfer
were considered for the study. Patients with preimplanta-
Higher pregnancy rates are obtained in some patient groups
tion genetic diagnosis for single-gene disorders or using
using day-3 blastomere biopsy with fresh transfer on day 4
donor oocytes were excluded from this study. Patients
who presented prior to onset of trophectoderm biopsy were
the advancement in the detection of the full chro-
provided only the day-3 biopsy option.
mosome complement available with array comparative
Several patients undergoing trophectoderm biopsy had
genomic hybridization (aCGH), embryos can be more fully
suffered repeated miscarriages and were diagnosed with
screened to avoid transferring embryos that do not contain
Asherman's syndrome or other uterine issues and subse-
a normal karyotype ). In addition, with
quently successfully used gestational carriers to carry their
improvement in media as well as culture conditions, blasto-
euploid embryos to term. These patients were excluded
cyst formation can reach an average of 40–60% (
from the study.
Blastocyst culture has been shown toimprove pregnancy and implantation rates by allowing
selection to occur in the Petri dish. The extended culturegives an embryo time to better express its potential and
All underwent ovarian stimulation involving: (i) luteal-phase
has become an invaluable tool for embryo selection.
down-regulation with a gonadtrophin-releasing hormone
Observing development in a cohort of embryos and basing
(GnRH) analogue; (ii) follicular-phase flare using GnRH ana-
selection of embryos for transfer on blastocyst morphology
logue; and (iii) antagonist-controlled stimulations in which
alone gives better implantation and birth rates
GnRH antagonist was administered when lead follicles
However, there are some embryos that arrest at the
achieved diameters of roughly 12 mm. All cycles included
cleavage stage: they simply stop growing. These embryos
daily injections of gonadotrophins, either recombinant FSH
prove that they have no further potential, and most have
(Gonal F, EMD Serono, Rockland, MA, USA; or Follistim,
degraded DNA and/or are aneuploid (
Merck, Whitehouse Station, NJ, USA) or a combination of
work hoped to improve success by combining two
recombinant FSH and human menopausal gonadotrophin
selection tools: selecting euploid embryos (genetic selec-
(Menopur, Merck). Injection of human chorionic gonadotro-
tion) that had achieved the blastocyst stage (developmental
phin (HCG; 10,000 IU urinary HCG or two vials of
recombinant HCG (Ovidrel; EMD Serono) or leuprolide ace-
performing trophectoderm biopsy and 24-chromosome pre-
tate (Lupron, Tap Pharmaceuticals, Lake Forrest, IL, USA)
implantation genetic screening using aCGH onlyon embryos
plus 1000 IU urinary HCG was used to trigger the final mat-
reaching the blastocyst stage (
uration, when at least two follicles had reached 18 mm,
). We compared the euploidy rates of day-3
although individualized criteria are often used when a
blastomere biopsy to trophectoderm biopsy at the blastocyst
patient has had prior cycles. The oocyte retrieval was
stage to determine if extended embryo culture also selects
scheduled 36 h after the trigger.
for euploid status and then compared pregnancy and implan-tation rates between the two different days of biopsy.
Day-3 biopsy and genetic screening
Cleavage-stage blastomere biopsy was performed on day-3embryos that had at least 4 cells. A hole was created in
the zona pellucida using acidified Tyrode's solution (Sigma,St Louis, MO, USA). Calcium/magnesium-free medium
presented to New York University Fertility Center
(Global, Guilford, CT, USA) was used to loosen the cell–cell
with interest in preimplantation genetic screening since it
adhesion allowing for less traumatic suction removal of the
had been performed here for years prior to this study. The
cell from the embryo. The biopsied cell was then loaded
use of aCGH as the method for genetic screening began in
into a PCR tube (Eppendorf) labelled with the corresponding
2010 as the centre was convinced that screening all chromo-
embryo number and sent to the reference laboratory
somes was an improvement over screening a limited number
(Reprogenetics, Livingston, NJ, USA) on dry ice for analysis
of chromosomes using FISH probes. Recruiting patients for a
using whole-genome amplification. Embryos were then
new unproven technique (trophectoderm biopsy) was diffi-
placed back in culture until aCGH results were obtained in
cult. Laboratory personnel and physicians counselled
time for a day-5 embryo transfer. The best-quality euploid
Comparing euploid rates of blastomere versus trophectoderm biopsies
embryo(s) were then transferred using a Sureview Wallace
catheter (Smith's Medical, UK) with ultrasound guidance.
Progesterone supplementation was provided to patients
total of 305 patients underwent ovarian stimulation: 131
with fresh transfers of biopsied embryos by injection of pro-
in anticipation of blastomere biopsy and 174 in anticipation
gesterone in oil or by vaginal administration (Crinone,
of trophectoderm biopsy. There were no significant differ-
Endometrin or suppositiories) beginning on the day follow-
ences in patient age, maximum day-2 or -3 FSH or inci-
ing oocyte retrieval.
dences of most of the diagnoses or stimulation protocolsbetween the day-3 and trophectoderm biopsy groups
Trophectoderm biopsy and genetic screening
Patients in the trophectoderm biopsy group hada higher incidence of uterine factor infertility. Oocyte
For blastocyst biopsy, a narrow channel was created in the
retrieval was cancelled because of poor ovarian response
zona pellucida using a laser (Cronus, Research Instruments,
in 9.9% (13/131) of patients in the day-3 biopsy group and
UK) on day 3. On days 5 and 6 and on rare occasions day 7,
4.6% (8/174) of patients in the trophectoderm biopsy group.
embryos were assessed and any fully differentiated
total of 284 patients underwent oocyte retrievals: 118
good-quality blastocyst was biopsied. Using suction, the
for day-3 biopsy and 166 for trophectoderm biopsy. Patient
trophectoderm cells extruding from the expanded blasto-
treatment parameters were not significantly different,
cyst were gently pulled and then a few pulses of the laser
including day-2 FSH and oestradiol concentrations, total
were used at cell junctions in order to safely remove a
gonadotrophin, FSH and/or human menopausal gonadotro-
few cells without disrupting the inner cell mass. The cells
phin administered and days of gonadotrophin administration
were washed and loaded into PCR tubes labelled with corre-
sponding embryo number and sent to the reference labora-
total, 1603 embryos were analysed (936 biopsied on
tory on dry ice for 24-chromosome analysis. Following
day 3, 667 biopsied at the blastocyst stage) over the
trophectoderm biopsy, blastocysts were vitrified using Sage
2.5-year period. Maternal age at biopsy was (mean ± stan-
(Trumbull, CT, USA) or Irvine (Santa Ana, CA, USA) media
dard deviation) 38.1 ± 4.3 years (range 22–47 years) and
and vitrification kits and CryoLocks (BioTech, Cummin,
was not significantly different between the two groups.
GA, USA) according to the manufacturer's instructions.
Trophectoderm biopsies were performed on day 5 (59.6%),
All biopsies were sent to a reference genetics laboratory
day 6 (38.7%) and day 7 (1.7%) just prior to vitrification.
for preimplantation genetic screening using whole-genome
was no difference between patient parameters in
amplification and aCGH as described previously (
the two biopsy groups when considering the numbers of
oocytes retrieved, patients with intracytoplasmic sperm
After the aCGH results were obtained, the patient's prep-
injection, mature oocytes, 2PN zygotes, embryos cultured
aration for transfer of vitrified–warmed embryos began with
beyond day 3 (extended culture) or cells in day-3 embryos
oral oestradiol tablets (Estrace; Warner Chilcott, Rockaway,
). There were significant differences between the
NJ, USA) beginning on day 2 of the next menstrual cycle.
number of embryos biopsied per patient (8.8 day-3 versus
Once the uterine lining was at least 7 mm with a ring pattern,
4.7 trophectoderm biopsy; P < 0.0001). There were also sig-
injections of progesterone in oil (Watson Pharma, Parsippa-
nificant differences in the number of blastocysts forming on
ny, NJ, USA) or suppositories (prepared by local pharmacies)
days 5 or 6 (4.1 day-3 versus 5.3 trophectoderm biopsy;
were begun. On day 6 of progesterone, the desired number
P = 0.031) and the number of blastocysts that achieved
(generally one and sometimes two) euploid embryos were
stage 2 or greater (3.4 day-3 versus 4.7 trophectoderm
warmed using Sage or Irvine warming kits and then trans-
biopsy; P = 0.012; ).
ferred to the patient's uterus under ultrasound guidance.
Pregnancy results were obtained on day 28 of the cycle
and confirmed on day 35 with ultrasound on day 42–49 forpresence of intrauterine sac and fetal heart activity.
those 1603 embryos that were biopsied, 31.3% (n = 501)
Specific outcome measures included rates of euploidy,
were euploid, 62.1% were aneuploid (n = 995) and 6.7%
implantation and clinical pregnancy. Euploidy rate was cal-
(n = 107) had no diagnosis. There were 6.5 ± 4.6 embryos
culated using the number of euploid embryos divided by
(range 1–35) biopsied and 2.0 ± 3.0 (range 1–17) were
the total number of embryos that were biopsied. Implanta-
found to be normal. The proportion of biopsied embryos
tion rate was calculated as the number of intrauterine ges-
that were euploid was significantly larger following trophec-
tational sacs visualized on ultrasound divided by the total
toderm biopsy compared with day-3 biopsy (42% versus 24%
number of embryos transferred. A clinical pregnancy was
expressed per biopsied embryo, P < 0.0001; 32% versus 23%
defined as the presence of an intrauterine gestational
per biopsied patient, P = 0.011; The number of
sac(s) with fetal cardiac activity as documented by ultra-
euploid embryos per patient was not significantly different
sound. Variables in the study groups were compared by
between the day-3 and trophectoderm biopsy groups (2.1
chi-squared analyses and Fisher's exact test or Student's
t-test, as appropriate. Statistical analysis was performed
patients (29%) who had embryos biopsied on
using Microsoft Excel, SPSS software and/or GraphPad
day 3 had no euploid embryos. Twelve additional patients
online. Patients' acceptance of informed consent was indi-
with at least one euploid embryo had no euploid blastocysts
cated by their signatures in accordance with Institutional
at the time of transfer (day 5) or the following day (day 6).
Review Board protocol (NYU IRB no. 512-03373, approved
(These patients underwent transfer of euploid morulae or
10 October 2012).
euploid cleavage-stage embryos without blastocysts on
A Adler et al.
Characteristics of patients who underwent ovarian stimulation.
Maximum FSH (IU/l)
Diminished ovarian reserve
Ovulatory dysfunction (PCO)
Values are mean ± SD or % (n).
PCO = polycystic ovaries.
aP = 0.003.
Cycle and embryological data of patients who underwent oocyte retrieval.
Day-2 FSH (mIU/ml)
Day-2 oestradiol (pg/ml)
Gonadotrophin (total IU)
Days of gonadotrophin
Oestradiol (pg/ml) on trigger day
Patients with ICSI
Embryos in extended culture
Patients with biopsy
Values are mean ± SD or % (n).
HMG = human menopausal gonadotrophin; ICSI = intracytoplasmic sperm injection.
aP = 0.031.
bP = 0.012.
day 5.) Therefore, there were 43 patients (41%) in the blas-
had no euploid blastocysts. The incidence of patients with
tomere biopsy group with no euploid blastocysts on day 5 or
no euploid blastocysts was not significantly different when
6. Fifty-four patients who had trophectoderm biopsies (38%)
expressed per biopsied patient (41%, 43/106 versus 38%,
Comparing euploid rates of blastomere versus trophectoderm biopsies
Results of patients who underwent embryo biopsy.
Embryos with no determination
Embryos biopsied/biopsy patient
Euploid embryos/biopsy patient
Euploid embryos/biopsied embryo (%)
Cycles with no euploid embryos
Cycles with no euploid blastocysts
Values are mean ± SD (total numbers in parentheses) or % (n).
NS = not statistically significant.
54/141), per retrieval (47%, 55/118 versus 48%, 79/166) or
significantly different (t-test, P = 0.0001), comparisons of
per cycle initiated (52% 68/131 versus 50%, 87/174).
clinical pregnancy rates may not be appropriate.
the euploid embryos that were transferred, 31 babies
Transfer and pregnancy results
were born in the blastomere biopsy group (25% of thosetransferred) and 45 babies were born in the trophectoderm
There were 75 embryo transfers in the blastomere biopsy
biopsy group (58% of those transferred). There were three
group and 68 in the trophectoderm biopsy group, for which
miscarriages and one stillbirth in the blastomere biopsy
125 embryos (1.7 ± 0.6 embryos per transfer) and 78
group (11.4%) versus six miscarriages in the trophectoderm
(1.2 ± 0.4 embryos per transfer) were transferred. There
biopsy group (15.4%). There were no misdiagnoses found
was a significantly higher implantation rate in the trophec-
in any of the babies born or in tissue recovered from the ter-
toderm biopsy group compared with the embryo biopsy
minations that occurred due to nonviable pregnancies.
group (60% versus 41%, respectively, P = 0.004), but the clin-
the blastomere biopsy group, there were 12 fresh
ical pregnancy rate was not significantly different (47% ver-
transfers that included only euploid nonblastocysts (moru-
sus 57%, respectively) (). However, since the
lae and cleavage-stage embryos). Only one pregnancy
numbers of embryos transferred in the two groups were
resulted from transfer of two morulae (implantation rate14%, 2/14). In contrast, when only euploid embryos weretransferred and the transferred embryos included at least
one blastocyst, the implantation rate was 44% (49/111)and was significantly different from the implantation rate
for nonblastocysts (Fisher's exact test, P = 0.043). Theimplantation rate of embryos biopsied on day 3 when blas-
tocysts were transferred (44%) was not significantly differ-ent
implantation rate of embryos undergoing trophectoderm
biopsy, vitrification, rewarming and transfer (58%, 45/78).
observations provide evidence to support three
important ideas: (i) extended culture enables selection of
embryos with a greater chance of implantation and live
delivery; (ii) selection of embryos that achieve the blasto-
Implantation rates and clinical pregnancy rates per
cyst stage enriches for euploid embryos; and (iii) extended
transfer for embryo and trophectoderm biopsies. Implantation
culture does not lead to a significant loss of euploid embryos
rates were significantly different between embryo and troph-
capable of implantation.
ectoderm biopsy (P = 0.004) when considering all patients with
present observations indicate that among euploid
embryo transfers. Clinical pregnancy rates were not signifi-
embryos biopsied on day 3, those that become blastocysts
cantly different between the two groups. CPR = clinical preg-
by the time of transfer are more likely to implant than those
IR = implantation
that do not become blastocysts by the time of transfer. It is
TEB = trophectoderm biopsy.
clear that transferred euploid blastocysts selected on day 5
A Adler et al.
have greater potential for implantation than euploid
Advances in cryobiology, specifically vitrification, have
embryos that had not reached the blastocyst stage at trans-
allowed for cryopreservation and very high post-warming
fer. This suggests that there is a qualitative component of
survival of the blastocysts post biopsy. Trophectoderm
the embryo that is associated with ability to implant but
biopsy would not be universally feasible without reliable
that is unassociated with embryo ploidy. This qualitative
cryopreservation techniques. The ability to vitrify blasto-
component may simply be the embryo's potential to implant
cysts with reliable, excellent warming results, allows time
or a more complex embryo–uterus synchrony issue. This
for analysis ) and minimal loss of precious,
confirms Munne's results on discarded embryos and mor-
euploid embryos. Also there is evidence that an unstimu-
phology along with also confirming day-5 embryo transfer
lated cycle provides a potentially superior uterine environ-
yielding higher pregnancy and implantation rates (
). Extended culture
transfer (). This allowed for transfer of
enables selection of embryos with a greater chance of
warmed embryos in a programmed warming cycle. Transfer
implantation and live delivery.
of vitrified–warmed euploid blastocysts was certainly not
data demonstrate that embryos biopsied at the blas-
inferior to transfer of fresh euploid blastocysts in the cur-
tocyst stage (trophectoderm biopsy) have a higher euploidy
rent study centre. In addition, the implantation rate of vit-
rate than embryos biopsied as cleavage-stage embryos
rified, euploid blastocysts was significantly greater than
(embryo biopsy). Extending culture and performing biopsy
implantation rate of fresh transferred embryos selected
at the blastocyst stage also results in lower aneuploidy rates
solely based on euploidy. It has been suggested that the
as compared with day-3 biopsy. The selection process that
uterine environment after exogenous oestrogen and proges-
occurs in the Petri dish eliminates the need to biopsy those
terone may be less prone to detrimental effects thought to
embryos not competent to advance beyond the cleavage
occur during ovarian stimulation. The success with this
stage and supports the concept that selection is occurring
approach demonstrates that single warmed euploid embryo
in the laboratory. Biopsying at the blastocyst stage identi-
transfer is an extremely effective method for achieving
fies only those embryos with the best chance for being chro-
mosomally normal and developmentally competent. This is
Numbers of embryos per patient undergoing extended
potentially the reason that extended culture provides higher
culture (beyond day 3) and the number of cells in embryos
pregnancy, implantation and live birth rates. Selection of
(on day 3) were not significantly different. In contrast, from
embryos that achieve the blastocyst stage enriches for
this similar number of embryos with similar quality, a signif-
icantly lower number of blastocysts and blastocysts (stage 2
distinction should be made between euploid embryos
or greater) arose in the blastomere biopsy group compared
and euploid blastocysts in the blastomere biopsy group
with the trophectoderm biopsy group. The number of
where some of the biopsied embryos found to be euploid
euploid embryos averaged 1.9 ± 2.3 per retrieval following
failed to progress to the blastocyst stage by the time of
blastomere biopsy. This number declined to 1.2 ± 1.6
transfer (day 5) or cryopreservation (day 6). This attrition
euploid blastocysts on day 5 following blastomere biopsy
accounts for the difference between numbers of euploid
due to failure of biopsied embryos to progress to the blasto-
embryos and euploid blastocysts in the blastomere biopsy
cyst stage. The performance of day-3 biopsy is one remark-
group. In the trophectoderm biopsy group, only blastocysts
ably different feature that stands out when comparing these
were biopsied so there was no difference between the num-
two groups of embryos. This suggests that day-3 biopsy itself
ber of euploid embryos and the number of euploid blasto-
is responsible for poorer development to the blastocyst
cysts. The enrichment in euploid embryos obtained by
stage and supports the contention of
selection of blastocysts for biopsy was achieved with no sig-
that blastomere biopsy on day 3 is detrimental to
nificant loss of euploid embryos since neither the number of
embryo development, although this study cannot exclude
euploid embryos per patient nor the number of euploid blas-
the possibility of simple, inherent poor quality of some of
tocysts per patient was significantly different when compar-
the day-3 euploid embryos. The number of euploid blasto-
ing the two biopsy groups. Excluding the embryos that failed
cysts averaged 1.7 ± 2.8 following trophectoderm biopsy.
to progress to become blastocysts from testing had no
The lack of significance between the numbers of euploid
impact on the patient other than to reduce the number of
blastocysts with embryo versus trophectoderm biopsy sug-
embryos biopsied. Extended culture does not lead to a sig-
gests that there was no significant loss of euploid embryos
nificant loss of euploid embryos capable of implantation.
or blastocysts in association with extended culture without
advantages of trophectoderm biopsy over blasto-
biopsy. This lack of significance gives confidence in delaying
mere biopsy are not only selection, but also with trophecto-
biopsy to the blastocyst stage.
derm biopsy more cells can be removed, compared with one
The limitations of this study are that it is retrospective
blastomere at day 3 (). This permits
and that the study was performed longitudinally. The intent
a more robust amplification and aneuploidy assessment.
of this paper was to describe this study centre's experience
Although there are more cells removed for testing, a lesser
with implementing trophectoderm biopsy and some notable
percentage of the embryo is removed and the inner mass
observations about the success of trophectoderm biopsy rel-
cells destined for fetal development are not compromised,
ative to blastomere biopsy. Despite its longitudinal nature,
presumably avoiding damage to the tissue that becomes the
the patients in the two study groups were quite similar as
fetus. Along with the advanced development at the blasto-
indicated in which show that the patients'
cyst stage, there is evidence of less mosaicism found com-
ages, ovarian reserves, diagnoses, treatment parameters
pared with that of day-3 embryos (
Comparing euploid rates of blastomere versus trophectoderm biopsies
similarity between study groups demonstrates that compar-
isons of outcomes are meaningful.
In conclusion, by extending embryo culture to the blasto-
cyst stage, a selection process occurs that enriches for
euploid embryos. This further elucidates why higher preg-
nancy, implantation and live birth rates can be achieved
with blastocyst transfer in unscreened embryos compared
with day-3 transfer. This is accomplished by eliminating
those embryos not competent enough to develop to the
blastocyst stage in addition to enrichment for euploidy.
However, trophectoderm biopsy adds a further tool by being
able to screen out blastocysts (viable embryos) that are
aneuploid, thereby improving chances of implantation by a
normal embryo and delivering a healthy, chromosomally
normal baby. Many morphologically normal blastocysts are
aneuploid and selecting only euploid embryos lowers mis-
carriage rates ). Combining
extended culture, trophectoderm biopsy and aneuploidy
assessment by aCGH and subsequent vitrification can pro-
vide a highly efficient means of achieving singleton euploid
pregnancies in IVF.
Thanks to Tsai-Ling (Cindy) Lee, Anne Goldstein-Tufaro,
Yael Kramer, Fran Hooper and Imelda Weill. In addition,
the authors thank all of the members of the NYU Fertility
Centre as well as the Reprogenetics team.
Declaration: The authors report no financial or commercial
conflicts of interest.
Received 9 January 2013; refereed 26 November 2013; accepted 27
TITLE: Current trends in sample preparation for growth promoter and veterinary drug residue analysis AUTHORS Brian Kinsella, John O'Mahony, Edward Malone, Mary Moloney, Helen Cantwell, AmbroseFurey, Martin Danaher This article is provided by the author(s) and Teagasc T-Stór in accordance with publisher policies. Please cite the published version. The correct citation is available in the T-Stór record for this article.
TURBULENT INVERSION AND ENTRAINMENT INTO STRATOCUMULUS TOPPED Szymon P. Malinowski1, Marta K. Kopeć1, Wojciech Kumala1, Katarzyna Nurowska1 Hermann Gerber2, DjamalKhelif3 1University of Warsaw, Faculty of Physics, Institute of Geophysics, Pasteura 7, 02-093 2Gerber Scientific Inc., Reston, VA, USA. 3Department of Mechanical & Aerospace Engineering and Earth System Science, University