The Avotaynu DNA Project processes each human DNA sample through a series of highly controlled steps designed to extract, amplify, and analyze genetic information for ancestry and genealogical research. Here’s a detailed description of that process from collection to result generation:
1. Sample Collection and Kit Registration
- Collection Method:
The Avotaynu Project uses a buccal swab kit, not a saliva tube. The user rubs two sterile swabs along the inside of their cheeks to collect epithelial cells. - Preservation:
Each swab is placed in two small tubes containing lyophilizing (drying) buffer that stabilizes the DNA at room temperature, protecting it from degradation during shipping. - Registration:
The Avotaynu assignes each sample with unique kit number and barcode , linking the physical sample to their digital profile. All participant identifying information is removed from each sample before further processing by the lab of GenebyGene, Inc. (Family Tree DNA) in Houston, Texas.
2. Receipt and Accessioning
- Chain of Custody:
On arrival at at laboratory of the FTDNA lab in Houston, the FTDNA staff scan each kit’s barcode into the system. It is then logged, labeled, and tracked through all subsequent steps under a Laboratory Information Management System (LIMS). - Quality Inspection:
Technicians confirm both swabs are intact and dry before proceeding.
3. DNA Extraction
- Purpose:
The goal is to isolate genomic DNA from the epithelial cells collected on the swab. - Method:
Cells are lysed (broken open) using enzymatic digestion (proteinase K and buffer solutions).
DNA is purified through magnetic bead–based or silica column extraction. - Quality Check:
DNA concentration and purity are measured with spectrophotometry or fluorescence quantification (e.g., PicoGreen assays).
Samples below minimum thresholds may be reprocessed using the second swab.
4. DNA Amplification (PCR)
- Polymerase Chain Reaction (PCR):
FTDNA amplifies (copies) specific DNA regions relevant to the test ordered—such as Y-chromosome STR and SNP regions, mitochondrial DNA, or autosomal SNPs. - Test-Specific Targeting:
- Y-DNA tests: Target short tandem repeats (STRs) and/or SNP markers on the Y-chromosome.
- mtDNA tests: Target the hypervariable regions (HVR1, HVR2, and coding regions).
5. Genotyping or Sequencing Fluorescent scanning determines whether the individual carries A/T/C/G variants at each locus.
- For Y-DNA STR Testing:
PCR products are run through capillary electrophoresis to measure the fragment lengths corresponding to each STR marker (e.g., DYS393, DYS385, etc.). - For Y-DNA SNP and mtDNA Tests:
FTDNA now uses Next-Generation Sequencing (NGS) on Illumina platforms (e.g., MiSeq) for high-resolution detection of SNP variants and full mtDNA sequences.
6. Data Processing and Quality Control
- Raw Data Extraction:
Fluorescent signals or NGS reads are converted into base calls and compared to a reference genome. - Bioinformatics Pipeline:
- For NGS: reads are aligned, filtered, and variant-called using FTDNA’s proprietary pipeline.
- For microarrays: SNP genotype calls are validated and phased.
- QC Metrics:
- Call rate thresholds (e.g., >98% for SNPs).
- Signal intensity uniformity.
- Concordance between duplicate runs when applicable.
- Samples failing QC may be re-amplified or re-extracted.
7. Result Interpretation and Database Matching
- Y-DNA Results:
STR and SNP values are compared against FTDNA’s extensive Y-chromosome haplotree, defining the customer’s haplogroup.
STR values are entered into the matching database to find other men with shared paternal ancestry. - mtDNA Results:
Variants are mapped to the RSRS reference, and haplogroup assignment follows the PhyloTree structure.
Matches are found among others with similar maternal-line mutations.
8. Reporting and User Access
- Once results pass all quality checks, the anonymized results are uploaded to the Avotaynu online dashboard.
- FTDNA provides to the Avotaynu DNA Project:
- Interactive match lists
- Downloadable raw data (Y-DNA, mtDNA, autosomal)
9. Long-Term Storage and Future Testing
- FTDNA retains extracted DNA at −20°C in its DNA archive, allowing customers to order additional tests (e.g., upgrading from Y-37 to Big Y-700) without resubmitting a sample.
✅ Summary Workflow Overview
| Step | Stage | Key Technique |
|---|---|---|
| 1 | Collection | Buccal swab with stabilizer |
| 2 | Accessioning | Barcode tracking in LIMS |
| 3 | Extraction | Magnetic bead / silica column DNA isolation |
| 4 | Amplification | PCR |
| 5 | Genotyping/Sequencing | Illumina microarray or NGS |
| 6 | QC | Signal, coverage, concordance checks |
| 7 | Analysis | Haplogroup assignment, segment matching |
| 8 | Reporting | Online dashboard, data download |
| 9 | Archiving | DNA stored for future upgrades |
