We all like to have strong references, don't we? New DNA reference material is becoming available. Proficiency programs in immunohematology and red cell genotyping have relied on fresh red cells and DNA from blood donations for decades. This approach may change in the near future. Permanent cell lines have been established as a reliable, stable and strong source for DNA. The FDA offers this DNA as reference material. Such DNA samples are characterized at unprecedented detail, and their nucleotide sequences are being established at great lengths. The samples are ideal material for assay development and validation. Their reference DNA sequences are indispensable for precision medicine and diagnostics utilizing next generation sequencing. We describe the insight gleaned from such strong reference material for long-range nucleotide sequencing and the current progress in reference DNA availability.