Species identification service

Species Identification Testing Service – DNA Barcoding, Morphological Analysis and Molecular Taxonomy for Biodiversity Research, Forensics and Regulatory Compliance

As an ISO/IEC 17025 accredited contract research laboratory, we offer specialised species identification services to Bulgarian and international clients in biotechnology, pharmaceuticals, food safety, agriculture, environmental monitoring, and forensics. Accurate species identification is critical for biodiversity conservation, invasive species detection, food authenticity (e.g., meat, fish, and herbal products), timber tracking, wildlife crime investigation, and medical diagnostics. Our integrated approach combines morphological characterisation (by trained taxonomists) with molecular techniques – including DNA barcoding, multilocus phylogenetic analysis, real‑time PCR, and whole‑genome sequencing – to provide definitive identification from a wide range of biological samples. All methods are aligned with ISO 18086 (Foodstuffs – DNA barcoding for fish and meat), ISO 21569 (Detection of genetically modified organisms), ISO 24187 (Principles for DNA barcoding), BDS (Bulgarian Institute for Standardisation) guidelines, and Eurofins forensic standards. Our reports are recognised by the Bulgarian Food Safety Agency (BFSA), the Ministry of Environment and Water (MOEW), the National Centre for Infectious and Parasitic Diseases (NCIPD), and international conservation bodies (CITES) for regulatory compliance and enforcement.

Sample Types and Biological Materials We Analyse

Our laboratory handles a diverse range of biological materials, from tissue samples to environmental DNA. Typical test articles include:

• Animal tissues – muscle, skin, hair, feathers, scales, bones, teeth, and blood from mammals, birds, reptiles, fish, and amphibians
• Plant materials – leaves, seeds, roots, wood, bark, fruit, and pollen
• Fungal samples – fruiting bodies (mushrooms), mycelium, and spores
• Microorganisms – bacterial and fungal isolates from environmental, clinical, or industrial sources
• Processed and mixed products – meat and fish products (cooked, canned, frozen), herbal supplements, spices, timber, and animal feed
• Environmental DNA (eDNA) – water, sediment, soil, and air samples for presence/absence screening
• Forensic samples – degraded, processed, or trace samples from crime scenes, customs seizures, or wildlife poaching incidents
• Pure cultures and cryopreserved specimens – for reference collection and strain verification

DNA Barcoding – Standardised Molecular Identification

DNA barcoding is our primary molecular tool for species identification, targeting standardised genetic markers with established reference databases.

• COI (Cytochrome c oxidase subunit I) for animals – we amplify the standard 658‑bp fragment of the COI gene using universal or group‑specific primers (e.g., LCO1490/HCO2198). The PCR product is sequenced (Sanger or NGS) and compared against the Barcode of Life Data System (BOLD) and GenBank reference databases. A match with a representative sequence (≥ 98 % similarity) provides reliable species‑level identification for most vertebrate and invertebrate taxa.
• ITS (Internal Transcribed Spacer) for fungi and plants – we amplify the ITS1‑5.8S‑ITS2 region, the official fungal barcode. For plants, we use the rbcL, matK, or trnH‑psbA loci as complementary markers to resolve closely related species.
• 16S rRNA / 18S rRNA for prokaryotes and eukaryotes – we amplify the V3‑V4 region of the 16S rRNA gene (for bacteria and archaea) or the V4 region of the 18S rRNA gene (for protists and other eukaryotes). These markers are used for the identification of environmental samples and complex microbial communities.
• Species‑specific multiplex PCR – for rapid screening of common food fraud targets (e.g., meat species, fish species), we use multiplex PCR panels that can identify up to 12 species in a single reaction, reducing time and cost.
• Real‑time PCR (qPCR) for quantitation – we can perform quantitative real‑time PCR (TaqMan or SYBR Green) to detect and quantify specific species in mixed samples, such as determining the percentage of a particular meat in a product blend. The limit of detection (LOD) is typically 0.01‑0.1 % for most species.

Morphological Identification – Classical Taxonomy and Expert Analysis

For certain taxa, especially when molecular methods are inconclusive or when reference sequences are lacking, we provide morphological identification by experienced taxonomists.

• Macroscopic and microscopic examination – we use digital microscopy, stereomicroscopy, and scanning electron microscopy (SEM) to examine diagnostic features: for plants, leaf venation, trichome type, and floral parts; for fungi, spore shape, size, and ornamentation; for insects, wing venation, genitalia, and colour patterns.
• Identification keys – we follow regional and international dichotomous keys, including the Flora Europaea, Fauna Europaea, and taxonomic monographs for specific groups (e.g., Coleoptera, Lepidoptera, Hymenoptera).
• Comparison with reference collections – we cross‑reference the specimen with our in‑house reference collection (vouchers, dried specimens, and microscope slides) and with regional natural history museum collections to confirm identification.
• Specialised staining techniques – for species that require differentiation, we apply special stains (e.g., lactophenol cotton blue for fungi, Fast Green for plant tissues, and Gram staining for bacteria) to enhance morphological details.

Phylogenetic and Evolutionary Analyses – Resolving Complex Cases

For samples that represent novel or unresolved lineages, we perform multi‑locus phylogenetic analysis to place the unknown species within the tree of life.

• Multi‑locus sequence typing (MLST) – we sequence multiple (4‑7) housekeeping genes (e.g., for bacteria, the 16S rRNA, rpoB, groEL genes) and construct a concatenated phylogenetic tree using Bayesian (MrBayes) or Maximum Likelihood (RAxML) methods. This approach can identify species that are difficult to assign using a single marker (e.g., cryptic species within a morphologically uniform group).
• Whole‑genome sequencing (WGS) for strain‑level resolution – for bacterial or fungal isolates that require detailed identification (e.g., for epidemiological investigations or biosecurity), we perform WGS and use average nucleotide identity (ANI) and digital DNA‑DNA hybridisation (dDDH) to identify the species and strain with high confidence (≥ 95 % ANI).
• DNA metabarcoding – identification of mixed communities – for environmental samples (water, soil, gut contents), we use high‑throughput sequencing of amplicons and analyse the data using QIIME2 or Mothur pipelines to obtain a species‑level community profile.
• Comparative genomics – detection of introgression and hybridisation – for samples suspected of hybrid origin, we compare whole‑genome data with the genomes of parent species to detect signatures of admixture (e.g., D‑statistic, F‑statistic).

Case‑Specific Applications – Forensics, Biosecurity and Trade Compliance

Our species identification service is tailored to the specific needs of various regulatory and enforcement contexts. We offer the following specialised case‑specific applications.

• Wildlife forensics – CITES enforcement – we identify protected species from confiscated materials (e.g., ivory, animal parts, timber) using DNA barcoding and morphological analysis, supporting the Bulgarian and European enforcement agencies (EU‑TWIX).
• Food authentication – meat and fish fraud – we perform DNA barcoding and species‑specific PCR to confirm the declared identity of meat, fish, and seafood products, meeting the requirements of the Bulgarian Food Safety Agency (BFSA) and the EU Food Fraud Network (FFN).
• Timber and wood identification – combating illegal logging – we use wood anatomy (macroscopic and microscopic) and DNA barcoding (using the ITS and trnH‑psbA markers) to determine the genus and, where possible, the species of timber, supporting the Bulgarian Forestry Executive Agency and EU Timber Regulation.
• Invasive species detection – environmental monitoring – we use eDNA metabarcoding and species‑specific qPCR for the early detection of invasive species (e.g., Reynoutria japonica, Ailanthus altissima, Anoplophora glabripennis) for the Bulgarian Ministry of Environment and Water (MOEW) and regional park authorities.
• Medicinal plant and supplement testing – verifying herbal ingredients – we DNA‑barcode plant materials in herbal supplements (e.g., ginseng, echinacea, ginkgo) to detect substitution, adulteration, or contamination by look‑alike species, supporting the Bulgarian Drug Agency.
• Medical mycology – identification of pathogenic fungi – we use ITS sequencing and morphological analysis to identify fungal species from clinical isolates, aiding the Bulgarian healthcare system and reference laboratories.

Quality Control, Reference Databases and Traceability

To ensure the highest level of accuracy and reliability, we maintain rigorous internal quality control measures and use well‑curated reference databases.

• Reference databases – we access and cross‑reference the Barcode of Life Data System (BOLD), GenBank, and curated reference collections of Bulgarian and European flora and fauna.
• In‑house reference collection – we have developed a comprehensive in‑house reference collection of DNA barcodes for Bulgarian and European species, including invasive species and regulated taxa, which we use for validation of new identifications.
• Positive and negative controls – in each PCR run, we include positive controls (DNA from reference specimens) and negative controls (water or buffer) to monitor for contamination and ensure the reaction is working correctly.
• Sequencing quality checks – all sequences are checked for quality (Phred score ≥ 30), and the chromatograms are manually inspected for ambiguous bases; any sequences with uncertainty are re‑amplified and re‑sequenced.
• Blind testing and proficiency testing – we participate in external proficiency testing schemes (e.g., FAPAS, NIST) and conduct blind tests on internal samples to assess the reliability of our identification protocols.

Reporting and Data Delivery

Our final species identification report is structured to meet the needs of regulatory submissions, scientific publications, and internal use. The report includes:

• Sample information – sample ID, type, source, and collection details.
• Method summary – a description of the morphological and/or molecular methods used, including primers, PCR conditions, and sequencing protocols.
• Results – for DNA barcoding: the amplified sequence, the best‑matching reference sequence(s) with accession numbers, and the percentage similarity; for morphological analysis: diagnostic features and photographic documentation; for multi‑locus or WGS: the phylogenetic tree, ANI values, and strain typing.
• Interpretation – a clear statement of the identification at the species level (or higher, if not possible), with an assessment of confidence (e.g., “high confidence”, “moderate confidence”, or “tentative”).
• Statistical evaluation – for metabarcoding, the relative abundance and community composition; for forensic analysis, the match probability and likelihood ratio.
• Appendices – chromatograms, sequence alignments, phylogenetic trees, and images of specimens (macroscopic and microscopic) are included as supplementary material.

Report Acceptance & Compliance with Bulgarian and European Regulatory Standards

All species identification tests are performed under our ISO/IEC 17025 accreditation, and for forensic and enforcement purposes, we follow the ENFSI (European Network of Forensic Science Institutes) guidelines for DNA profiling. Our final reports are prepared in accordance with the requirements of the Bulgarian Food Safety Agency (BFSA), the Ministry of Environment and Water (MOEW), the National Centre for Infectious and Parasitic Diseases (NCIPD), and international bodies such as CITES and EUROPOL. Bilingual (Bulgarian/English) versions are available to facilitate submissions to national and European authorities and to support scientific publications and research collaborations.