Analyze Diet

Topic:Laboratory Methods

Laboratory methods in equine research encompass a variety of techniques and procedures used to analyze biological samples from horses to study health, disease, genetics, and physiology. These methods include hematological analyses, biochemical assays, molecular biology techniques, and microbiological cultures. Commonly utilized laboratory techniques involve blood tests for complete blood count (CBC) and serum chemistry, polymerase chain reaction (PCR) for genetic and infectious disease studies, and enzyme-linked immunosorbent assays (ELISA) for detecting specific proteins or antibodies. These methods provide valuable data that contribute to understanding equine health and disease mechanisms. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and outcomes of laboratory methods in the context of equine research.
Fractionation of calcium and magnesium in equine serum.
American journal of veterinary research    March 2, 2006   Volume 67, Issue 3 463-466 doi: 10.2460/ajvr.67.3.463
Lopez I, Estepa JC, Mendoza FJ, Mayer-Valor R, Aguilera-Tejero E.To establish reference values for protein-bound, ionized, and weak-acid complexed fractions of calcium and magnesium in equine serum and determine stability of ionized calcium (iCa) and ionized magnesium (iMg) in serum samples kept under various storage conditions. Methods: 28 clinically normal horses. Methods: Total calcium (tCa) and magnesium (tMg) in equine serum were fractionated by use of a micropartition system that allows separation of protein-bound calcium (pCa) and magnesium (pMg) and ultrafiltrable calcium (microCa) and magnesium (microMg) fractions. Serum concentrations of iCa and i...
Real-time polymerase chain reaction: a novel molecular diagnostic tool for equine infectious diseases.
Journal of veterinary internal medicine    February 25, 2006   Volume 20, Issue 1 3-12 doi: 10.1892/0891-6640(2006)20[3:rpcran]2.0.co;2
Pusterla N, Madigan JE, Leutenegger CM.The focus of rapid diagnosis of infectious disease of horses in the last decade has shifted from the conventional laboratory techniques of antigen detection, microscopy, and culture to molecular diagnosis of infectious agents. Equine practitioners must be able to interpret the use, limitations, and results of molecular diagnostic techniques, as they are increasingly integrated into routine microbiology laboratory protocols. Polymerase chain reaction (PCR) is the best-known and most successfully implemented diagnostic molecular technology to date. It can detect slow-growing, difficult-to-cultiv...
A 1.3-Mb interval map of equine homologs of HSA2.
Cytogenetic and genome research    February 18, 2006   Volume 112, Issue 3-4 227-234 doi: 10.1159/000089875
Wagner ML, Raudsepp T, Goh G, Agarwala R, Schaffer AA, Dranchak PK, Brinkmeyer-Langford C, Skow LC, Chowdhary BP, Mickelson JR.A comparative approach that utilizes information from more densely mapped or sequenced genomes is a proven and efficient means to increase our knowledge of the structure of the horse genome. Human chromosome 2 (HSA2), the second largest human chromosome, comprising 243 Mb, and containing 1246 known genes, corresponds to all or parts of three equine chromosomes. This report describes the assignment of 140 new markers (78 genes and 62 microsatellites) to the equine radiation hybrid (RH) map, and the anchoring of 24 of these markers to horse chromosomes by FISH. The updated equine RH maps for ECA...
Development of an indirect enzyme-linked immunosorbent assay for detecting equine serum antibodies to the lipopolysaccharide of Salmonella abortusequi.
Research in veterinary science    February 17, 2006   Volume 81, Issue 2 215-217 doi: 10.1016/j.rvsc.2005.11.004
Gall D, Nielsen K, Bermudez RM, Muñoz del Real MC, Halbert G, Groulx R, Moreno F, Chow EY, Checkley SL.An indirect enzyme-linked immunosorbent assay (IELISA) was developed for the detection of equine serum antibodies to lipopolysaccharide of Salmonella enterica subsp. enterica serovar Abortusequi (LPS), a causative organism of Equine Paratyphoid. The data presented demonstrates that horses immunized with S. abortusequi LPS developed antibodies detectable by the IELISA. By comparison, the tube agglutination test (TAT) did not detect antibody to S. abortusequi LPS as consistently as the IELISA. The data suggests that the IELISA may be a more suitable test for the detection of serum antibodies to ...
Kinetics of amyloid aggregation of mammal apomyoglobins and correlation with their amino acid sequences.
FEBS letters    February 17, 2006   Volume 580, Issue 6 1681-1684 doi: 10.1016/j.febslet.2006.02.018
Vilasi S, Dosi R, Iannuzzi C, Malmo C, Parente A, Irace G, Sirangelo I.In protein deposition disorders, a normally soluble protein is deposited as insoluble aggregates, referred to as amyloid. The intrinsic effects of specific mutations on the rates of protein aggregation and amyloid formation of unfolded polypeptide chains can be correlated with changes in hydrophobicity, propensity to convert alpha-helical to beta sheet conformation and charge. In this paper, we report the aggregation rates of buffalo, horse and bovine apomyoglobins. The experimental values were compared with the theoretical ones evaluated considering the amino acid differences among the sequen...
Genotyping of Toll-like receptor 4, myeloid differentiation factor 2 and CD-14 in the horse: an investigation into the influence of genetic polymorphisms on the LPS induced TNF-alpha response in equine whole blood.
Veterinary immunology and immunopathology    February 14, 2006   Volume 111, Issue 3-4 165-173 doi: 10.1016/j.vetimm.2005.12.003
Werners AH, Bull S, Vendrig JC, Smyth T, Bosch RR, Fink-Gremmels J, Bryant CE.The inter- and intra-species differences in the response to lipopolysaccharides (LPS) are well recognised in mammalian species. It has been hypothesized that these differences can be attributed to genetic polymorphisms in the components involved in LPS signal transduction. These components include the cluster of differentiation factor 14 (CD-14), a membrane bound protein on the surface of mononuclear cells that recognises LPS and a receptor complex consisting of Toll-like receptor-4 (TLR-4) and myeloid differentiation factor-2 (MD-2). Sequencing of these three proteins in humans and mice revea...
A monoclonal antibody to equine interleukin-4.
Veterinary immunology and immunopathology    February 9, 2006   Volume 110, Issue 3-4 363-367 doi: 10.1016/j.vetimm.2006.01.001
Wagner B, Hillegas JM, Antczak DF.Interleukin-4 (IL-4) is secreted by T helper type 2 cells, mast cells, basophils and eosinophils. Detection of IL-4 can contribute the evaluation of cellular immune responses during infectious diseases, immunological disorders or vaccination. We used recombinant equine IL-4 to generate a monoclonal antibody (mAb) to equine IL-4. The mAb detected recombinant IL-4 in mammalian cells transfected with different plasmids containing IL-4 cDNA. After mitogen stimulation of equine peripheral blood mononuclear cells, an intracellular protein was recognized by the new mAb in 1-2% of lymphocytes using fl...
Detection of the reemerging agent Burkholderia mallei in a recent outbreak of glanders in the United Arab Emirates by a newly developed fliP-based polymerase chain reaction assay.
Diagnostic microbiology and infectious disease    February 8, 2006   Volume 54, Issue 4 241-247 doi: 10.1016/j.diagmicrobio.2005.09.018
Scholz HC, Joseph M, Tomaso H, Al Dahouk S, Witte A, Kinne J, Hagen RM, Wernery R, Wernery U, Neubauer H.A polymerase chain reaction (PCR) assay targeting the flagellin P (fliP)-I S407A genomic region of Burkholderia mallei was developed for the specific detection of this organism in pure cultures and clinical samples from a recent outbreak of equine glanders. Primers deduced from the known fliP-IS407A sequence of B. mallei American Type Culture Collection (ATCC) 23344(T) allowed the specific amplification of a 989-bp fragment from each of the 20 B. mallei strains investigated, whereas other closely related organisms tested negative. The detection limit of the assay was 10 fg for purified DNA of ...
Evaluation of factors associated with positive IgM capture ELISA results in equids with clinical signs compatible with West Nile virus infection: 1,017 cases (2003).
Journal of the American Veterinary Medical Association    February 2, 2006   Volume 228, Issue 3 414-421 doi: 10.2460/javma.228.3.414
Tanner JM, Traub-Dargatz JL, Hill AE, Van Campen H, Knight AP, Cunningham WE, Salman MD.To describe the prevalence of West Nile virus (WNV) infection and evaluate factors associated with positive IgM capture ELISA results in equids with clinical signs compatible with WNV infection. Methods: Retrospective case series. Methods: Laboratory submission forms from 1,104 equids tested for WNV in Colorado in 2003. Methods: Submission forms accompanying samples submitted for detection of WNV via IgM capture ELISA were obtained from the Colorado state veterinarian and diagnostic laboratories performing the tests. Data on signalment, clinical signs, history of vaccination against WNV, and a...
[The carnivorous fungi hyphomycetes are natural regulators of the size of animal parasitic nematodes].
Meditsinskaia parazitologiia i parazitarnye bolezni    February 1, 2006   Issue 4 13-17 
Tepliakova TV, Efremova EA, Riabchikova EI.The carnivorous fungi hyphomycetes are natural enemies of soil nematodes. Laboratory tests examining the effect of the effective strain Duddingtonia flagrans T-89 on equine strongyle larvae have indicated that their size can be reduced 5-48-fold under the action of the fungus. Using helminth-infected mice as an example has ascertained that when the animals are fed a biopreparation, the chlamydial spores of the carnivorous fungus D. flagrans remain viable and continue their development in the excrements. The dead nematodes show cell structural impairments in all tissues and organs, which may be...
Expression of insulin-like growth factor binding proteins in healing tendon lesions.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society    January 26, 2006   Volume 24, Issue 2 183-192 doi: 10.1002/jor.20000
Dahlgren LA, Mohammed HO, Nixon AJ.he treatment of overuse tendon injuries with exogenous growth factors such as insulin-like growth factor-I (IGF-I) may facilitate an improved return to sustained athletic function. The biological effects of IGF-I are exerted under the control of a complex of IGF receptors, binding proteins, and proteases. This IGF system includes a family of six structurally related high-affinity IGF binding proteins (IGFBPs) that protect IGF-I from local proteases and restrict access of IGF-I to its receptor. This study describes the expression of the IGFBPs in flexor tendon after acute injury and during heal...
The redox couple of the cytochrome c cyanide complex: the contribution of heme iron ligation to the structural stability, chemical reactivity, and physiological behavior of horse cytochrome c.
Protein science : a publication of the Protein Society    January 26, 2006   Volume 15, Issue 2 234-241 doi: 10.1110/ps.051825906
Schejter A, Ryan MD, Blizzard ER, Zhang C, Margoliash E, Feinberg BA.Contrary to most heme proteins, ferrous cytochrome c does not bind ligands such as cyanide and CO. In order to quantify this observation, the redox potential of the ferric/ferrous cytochrome c-cyanide redox couple was determined for the first time by cyclic voltammetry. Its E0' was -240 mV versus SHE, equivalent to -23.2 kJ/mol. The entropy of reaction for the reduction of the cyanide complex was also determined. From a thermodynamic cycle that included this new value for the cyt c cyanide complex E0', the binding constant of cyanide to the reduced protein was estimated to be 4.7 x 10(-3) L M(...
Equine CCL11 induces eosinophil cytoskeletal reorganization and activation.
Inflammation research : official journal of the European Histamine Research Society ... [et al.]    January 24, 2006   Volume 55, Issue 1 46-52 doi: 10.1007/s00011-005-0007-3
Weston MC, Collins ME, Cunningham FM.To assess the biological effects of purified recombinant equine CCL11 on equine eosinophil function. Methods: Following stimulation of eosinophils from normal horses, the polymerised form of actin was measured by flow cytometry using fluorescently labelled phalloidin. Migration was determined in a 96 well plate chemotaxis assay using 8 microm pore membranes, and adherence of eosinophils to serum-coated plastic was assessed using a colorimetric assay for eosinophil peroxidase. Superoxide generation was measured by the reduction of cytochrome C in a colorimetric assay. Results: Equine CCL11 indu...
Molecular diagnosis and equine parasitology.
Veterinary parasitology    January 20, 2006   Volume 136, Issue 2 109-116 doi: 10.1016/j.vetpar.2005.12.006
Hodgkinson JE.The future implementation of improved and sustainable control strategies for the major equine parasites will be dependent on a greater insight into their basic biology, pathogenicity and epidemiology together with an enhanced ability for accurate diagnosis. This paper will provide a review of the current molecular methods under development for the detection of equine parasites and their application to current scientific questions. In particular, the strongyles are recognised as important pathogens of horses and recent advances made in the study of this parasitic group at the single species lev...
Regional differences in the in vitro penetration of hydrocortisone through equine skin.
Journal of veterinary pharmacology and therapeutics    January 20, 2006   Volume 29, Issue 1 25-30 doi: 10.1111/j.1365-2885.2006.00705.x
Mills PC, Cross SE.Little is known about the transdermal penetration of hydrocortisone in the horse and, although commercial formulations containing hydrocortisone are registered for topical use in the horse, there have been no studies investigating the movement of this glucocorticoid through different regions of equine skin. Skin was harvested from the thorax, groin and leg (dorsal metacarpal) regions of five Thoroughbred geldings and frozen (-20 degrees C) until required. Defrosted skin was placed in Franz-type diffusion cells and the amount of radiolabelled ((3)H) hydrocortisone, in a saturated solution of un...
The detection of anthelmintic resistance in nematodes of veterinary importance.
Veterinary parasitology    January 19, 2006   Volume 136, Issue 3-4 167-185 doi: 10.1016/j.vetpar.2005.11.019
Coles GC, Jackson F, Pomroy WE, Prichard RK, von Samson-Himmelstjerna G, Silvestre A, Taylor MA, Vercruysse J.Before revised World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines on the detection of anthelmintic resistance can be produced, validation of modified and new methods is required in laboratories in different parts of the world. There is a great need for improved methods of detection of anthelmintic resistance particularly for the detection of macrocyclic lactone resistance and for the detection of resistant nematodes in cattle. Therefore, revised and new methods are provided here for the detection of anthelmintic resistance in nematodes of ruminants, horses and ...
Evaluation of glucosamine levels in commercial equine oral supplements for joints.
Equine veterinary journal    January 18, 2006   Volume 38, Issue 1 93-95 doi: 10.2746/042516406775374306
Oke S, Aghazadeh-Habashi A, Weese JS, Jamali F.No abstract available
Constant rate infusion for topical ocular delivery in horses: a pilot study.
Veterinary ophthalmology    January 18, 2006   Volume 9, Issue 1 1-5 doi: 10.1111/j.1463-5224.2005.00424.x
Myrna KE, Herring IP.To assess the efficacy and kinetics of a continuous infusion modality for topical ophthalmic drug delivery via subpalpebral lavage in horses. Methods: Five ophthalmically normal horses Methods: A constant-rate continuous delivery pump was used to apply 0.01% fluorescein solution to the eyes of five ophthalmically normal horses via subpalpebral lavage. Fluorescein was applied at a rate of 0.14 mL/h for 72 h. Tear samples were collected from the ventral conjunctival fornix at regular intervals via capillary tube and tear fluorescein concentrations were determined via spectral assay. Laboratory s...
Molecular diagnosis of anthelmintic resistance.
Veterinary parasitology    January 18, 2006   Volume 136, Issue 2 99-107 doi: 10.1016/j.vetpar.2005.12.005
von Samson-Himmelstjerna G.Conventional and real time polymerase chain reaction-based tests have been developed for the diagnosis of anthelmintic resistance (AR) in populations of several small and large ruminant as well as horse gastro-intestinal nematode species. To date, molecular markers that correlate well with AR are available only for the detection of benzimidazole resistance. Recently, however, a single nucleotide polymorphism was found in vitro to be of functional relevance for reduced drug efficacy to macrocylic lactones. The focus of the present review, therefore, is the molecular mechanism of action of these...
Evaluation of a nested PCR test and bacterial culture of swabs from the nasal passages and from abscesses in relation to diagnosis of Streptococcus equi infection (strangles).
Equine veterinary journal    January 18, 2006   Volume 38, Issue 1 59-63 doi: 10.2746/042516406775374324
Grønbaek LM, Angen O, Vigre H, Olsen SN.Streptococcus equi is the cause of strangles in horses. To improve diagnostic sensitivity, development and evaluation of DNA-based methods are necessary. Objective: To evaluate diagnostic methods and observe the pattern of bacterial shedding during natural outbreaks. Methods: Two herds with natural outbreaks of strangles were visited over a period of 15 weeks and 323 samples originating from 35 horses investigated. The diagnostic use of a nested PCR test was evaluated using a collection of 165 isolates of Lancefield group C streptococci (species specificity) and swabs from nasal passages or fr...
Evolutionary movement of centromeres in horse, donkey, and zebra.
Genomics    January 18, 2006   Volume 87, Issue 6 777-782 doi: 10.1016/j.ygeno.2005.11.012
Carbone L, Nergadze SG, Magnani E, Misceo D, Francesca Cardone M, Roberto R, Bertoni L, Attolini C, Francesca Piras M, de Jong P, Raudsepp T....Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one. After a CR, the primary constriction and the centromeric function are localized in a new position while the order of physical markers on the chromosome remains unchanged. These events profoundly affect chromosomal architecture. Since horses, asses, and zebras, whose evolutionary divergence is relatively recent, show remarkable morphological similarity and capacity to interbreed despite their chromosomes differing co...
Detection of recombinant epoetin and darbepoetin alpha after subcutaneous administration in the horse.
Journal of analytical toxicology    December 27, 2005   Volume 29, Issue 8 835-837 doi: 10.1093/jat/29.8.835
Lasne F, Popot MA, Varlet-Marie E, Martin L, Martin JA, Bonnaire Y, Audran M, de Ceaurriz J.A direct detection method for anti-doping control of recombinant human erythropoietin (rHuEPO) abuse in racehorses is proposed. This method involves screening of plasma (or serum) by an enzyme-linked immunosorbent assay specific for human EPO and confirmation in urine samples by characterization of the urinary EPO isoelectric profile. This method was tested on horses that were administered epoetin alpha (rHuEPO) and the hyper-glycosylated form of this drug (darbepoetin alpha).
In vitro degradation of equine keratin by dermatophytes and other keratinophilic fungi.
Veterinary microbiology    December 27, 2005   Volume 114, Issue 3-4 352-358 doi: 10.1016/j.vetmic.2005.11.060
Apprich V, Spergser J, Rosengarten R, Stanek C.Keratinolytic properties of two dermatophytes (Microsporum gypseum, Trichophyton mentagrophytes) and three moulds (Scopulariopsis brevicaulis, Alternaria alternata, Geotrichum candidum) isolated from diseased equine hooves were examined to improve the understanding of pathogenic mechanisms leading to equine onychomycosis. Equine hoof horn material and skin, as well as hoof keratin and dermal keratin extracted from corresponding tissues, were used as sole carbon and nitrogen sources in five test tubes for each fungus. Within 18 days, supernatants of all tubes were repeatedly examined for kerati...
Molecular variability in different Indian isolates of equine herpesvirus-1.
Veterinary research communications    December 22, 2005   Volume 29, Issue 8 721-734 doi: 10.1007/s11259-005-3380-z
Gupta AK, Kaur D, Rattan B, Yadav MP.Three abortigenic Indian isolates of equine herpesvirus-1 (EHV-1) (Tohana, Hisar and Bikaner), along with two exotic abortigenic isolates (AB4 and V592) and another EHV-1 isolate (Jind) obtained from a case of perinatal foal mortality, were studied for variability. For this purpose, PCR and restriction endonuclease (RE) digestion techniques were used simultaneously as a DNA fingerprinting system. Nine different regions of EHV-1 virus were amplified by PCR using primer pairs specific for the regions and the products obtained from these regions were subsequently subjected to various restriction ...
Repeatability of 2 methods for assessment of insulin sensitivity and glucose dynamics in horses.
Journal of veterinary internal medicine    December 17, 2005   Volume 19, Issue 6 883-888 doi: 10.1892/0891-6640(2005)19[883:romfao]2.0.co;2
Pratt SE, Geor RJ, McCutcheon LJ.Both the euglycemic-hyperinsulinemic clamp (EHC) and minimal model analysis of the frequently sampled intravenous glucose tolerance test (FSIGT) have been applied for measurement of insulin sensitivity in horses. However, no published data are available on the reproducibility of these methods. Therefore, the objective of this study was to evaluate the variation and repeatability of measures of glucose dynamics and insulin sensitivity in horses derived from minimal model analysis of the FSIGT and from the EHC method. Six healthy horses underwent both the FSIGT and EHC on 2 occasions over a 4-we...
In vitro effects of bethanechol on equine gastrointestinal contractility and functional characterization of involved muscarinic receptor subtypes.
Journal of veterinary pharmacology and therapeutics    December 14, 2005   Volume 28, Issue 6 565-574 doi: 10.1111/j.1365-2885.2005.00693.x
Marti M, Mevissen M, Althaus H, Steiner A.The goal of this study was to investigate the effect of bethanechol (BeCh) on contractility patterns of smooth muscle preparations of equine duodenum descendens, jejunum, caecum and pelvic flexure in vitro. Concentration-response relationships were developed for BeCh using in vitro assays with and without preincubation of muscarinic (M) receptor antagonists for M2 and M3 receptors. BeCh induced a significant, concentration-dependent increase in contractile response in equine intestine in specimens with circular orientation. The maximal effect was largest for jejunal specimens with no differenc...
Evaluation of coexpression of microsomal prostaglandin E synthase-1 and cyclooxygenase-2 in interleukin-1-stimulated equine articular chondrocytes.
American journal of veterinary research    December 13, 2005   Volume 66, Issue 11 1985-1991 doi: 10.2460/ajvr.2005.66.1985
Farley J, Sirois J, MacFarlane PH, Kombé A, Laverty S.To characterize expression of cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) and regulation of prostaglandin E2 (PGE2) production by equine articular chondrocytes. Methods: Articular cartilage from the metacarpophalangeal joints of 7 adult horses. Methods: Equine chondrocyte monolayer cultures were stimulated with different concentrations (2.5, 5, 10, and 20 ng/mL) of recombinant human interleukin-1beta (rhIL-1beta) for 24 hours and then with rhIL-1beta (5 ng/mL) for 3, 6, 9, 12, and 24 hours. Concentration of PGE2 in the media was measured via radioimmunoassay. T...
Efficacy demonstration of tetanus vaccines by double antigen ELISA.
Pharmeuropa bio    December 13, 2005   Volume 2005, Issue 1 31-52 
Rosskopf U, Noeske K, Werner E.This paper describes a double antigen ELISA (DAE) for rapid, specific and reliable assessment of the antitetanus immune status of horses and sheep. Compared with the indirect ELISA, the double antigen ELISA has the advantage of species-independent testing of sera. Thanks to its test design, it is more specific since the detected antibodies are forced to bind tetanus toxoid twice. In addition, it is very sensitive to tetanus antibodies, enabling the detection of low antibody titres, in range which is relevant for the assessment of the protective status (tetanus toxin neutralising antibodies). T...
Development of an enzyme-linked immunosorbent assay for specific equine neutrophil myeloperoxidase measurement in blood. Franck T, Grulke S, Deby-Dupont G, Deby C, Duvivier H, Peters F, Serteyn D.Equine inflammatory disease is accompanied by a neutrophil activation resulting in the release of granulocytic enzyme myeloperoxidase (MPO). To measure MPO in horse plasma as marker of neutrophil activation, the authors purified equine neutrophil MPO and developed a specific enzyme immunoassay using 2 specific polyclonal antibodies obtained from rabbit (primary antibody) and guinea pig (secondary antibody). The sandwich complex "primary antibody-MPO-secondary antibody" was detected using a goat anti-guinea pig immunoglobulin antibody conjugated to alkaline phosphatase. The enzyme-linked immuno...
Isolation of equine herpesvirus-2 from the lung of an aborted fetus. Galosi CM, de la Paz VC, Fernández LC, Martinez JP, Craig MI, Barrandeguy M, Etcheverrrigaray ME.This study describes the isolation of equine herpesvirus-2 (EHV-2) from the lung of an aborted equine fetus in Argentina. The isolated virus was confirmed as EHV-2 by indirect immunofluorescence using a rabbit anti-EHV-2 polyclonal antiserum and by virus-neutralization test using an equine polyclonal antibody against EHV-2. Restriction endonuclease DNA fingerprinting with BamHI also confirmed the identity of the virus as EHV-2. Furthermore, viral nucleic acid was detected by polymerase chain reaction from the original lung sample and from the DNA obtained from cells infected with the virus iso...