Jerold M. Lowenstein

Identification of archaeological blood proteins: A cautionarynote

Abstract Submission of archaeological specimens for blood residue analysis is being promoted increasingly as a necessary stepin the routine study of ancient remains and artefact assemblages. The validity and usefulness of this practice, however, are unknown, and the accuracy and comparability of the different laboratory tests employed have never been examined adequately. The most promising methods for detecting blood proteins and determining species of origin are based on recognized standard medical and forensic procedures. Application of these various techniques to archaeological residues, however, remains experimental. Independent investigators, using different approaches, have been reporting successful identifications of prehistoric proteins with increasing frequency and confidence. Despite perceived internal consistency and accuracy of each analytic technique, external consistency and comparability of reported results have not been demonstrated. A central question relates to blood protein survival over time and the relative capability of the different laboratory methods to detect, identify and discriminate accurately between the ancient degraded proteins. The purpose of this paper is to address some of these issues, and to sensitize both researchers and archaeologists to the need for caution in reporting and interpreting unconfirmed test results on ancient blood proteins.

Species-specific proteins in fossils

With a solid-phase radioimmunoassay it has been possible to detect species-specific collagen and albumin in fossils as old as 1.9 million years. This technique may provide new data on the genetic relations of fossil species to each other and to living forms.

Immunospecificity of albumin detected in 1.6 million-year-old fossils from Venta Micena in Orce, Granada, Spain

The Orce skull fragment from southern Spain, dated at 1.6 Myr, has been a subject of heated controversy since it was first discovered in 1982. If it is hominid, as its discoverers contend, it is by far the oldest fossil hominid yet found in western Europe and implies that human populations settled this region much earlier than was previously realized. Numerous stone artifacts found at the Orce sites provide evidence that hominids were indeed present there in the Lower Pleistocene. Some paleontologists maintain that the 8 cm diameter occipital fragment is from a horse, not a hominid. Two independent investigations of the residual proteins in the skull were undertaken, one at the University of Granada in Spain, the other at the University of California, San Francisco. Two immunological methods of comparable sensitivity were employed for detection and species attribution of protein extracted from fossil bone: the Granada team used an enzyme-linked-immunosorbent assay (ELISA), and the UCSF team used a radioimmunoassay (RIA). Both teams obtained reactions characteristic of human albumin in the Orce skull and horse albumin in some of the horse fossils. These results support the lithic evidence that hominids were living in Andalusia 1.6 million years ago.

Elevated Serum TSH in Human Thyroid Cancer

Serum TSH levels, determined by a very sensitive immunofluorescent assay, were found to be consistently higher in euthyroid individuals with thyroid cancer than in normal persons or those with other t

Scyphomedusae and their polyps are the same immunologically: Implications for systematics

1. Polyp and medusa of the scyphozoans Aurelia aurita and Pelagia colorata (phylum Cnidaria) are indistinguishable by radioimmunoassay of whole animals, yet differ from other cnidarians against which they were tested. 2. We infer that proteins distinguishing species swamp those that differentiate the two (very distinct) life history phases. 3. Thus, at least for some taxa and some systematic techniques analyzing proteins, using organisms at the same developmental phase may be unnecessary, contrary to conventional wisdom.

Immunospecific albumin in fossil pack rat, porcupine and hyrax urine

Certain cave-dwelling mammals, notably North American pack rats (Neotoma spp.), inadvertently preserve plant fragments and other debris in large masses of crystallized urine (e.g., amberat) known as middens. The excellent preservation of plant macrofossils in these ubiquitous deposits invites application of new techniques permitting DNA extractions from mummified plant tissue [1, 2]. In a recent study, it was found that DNA yields in plant tissue from pack rat middens decreased rapidly during the first 1 000 to 2000 years, though 45 000-year-old material still yielded high-molecular-weight DNA [1]. Now, radioimmunoassay (RIA) of the ancient pack rat urine that protects this plant DNA from oxidation shows the persistence of highly specific albumin, with a similar two-phase pattern of decline in albumin immunoreactivity between 0 and 20000 years before present (B,P.). RIA analysis of urine samples form North American porcupine (Erethizon dorsatum) and South African hyrax (Procavia sp.) middens also confirms the preservation of group-specific albumin in these specimens. Over the past 30 years, rich assemblages of plant macrofossils have been studied in more than 1 000 pack rat middens in the arid interior of western North America [3]. In a region where wetlands are scarce, these assemblages have supplanted lacustrine pollen records as a touchstone for studying vegetation dynamics and climatic change in radiocarbon time (the last 40 000 years). Similar middens produced by other animals are now known worldwide, principally porcupines in North America [4], hyraxes in Africa [5] and the Middle East [6], stick-nest rats (Leporillus) in Australia [7, 8], and leaf-eared mice (Phyllotis) in South America [9]. The presence of volatiles in middens thousands of years old, indicated by release of a strong, musky odor during routine soaking in water, implies preservation of proteins that may retain characteristic features of the taxon. We offer RIA as one technique that can be used to detect the presence of highly specific proteins and thus, to identify the organism producing a fossil midden where other diagnostic information is lacking, e.g., Cricetideae vs. Chinchillidae in the foothills of the Andes in Argentina. Previously, immunologically specific albumin was detected by RIA in frozen mammoth tissue and in mummified tissue of the extinct Tasmanian wolf [10], in bones of the extinct Stellers sea cow [11], and in blood stains on ancient tools and weapons [12]. Urine normally contains readily measurable trace amounts of serum albumin, a water-soluble protein that should persevere within the crystallized matrix of middens found in dry caves. For pack rats, the mineralogy of the crystallized urine is primarily calcium oxalates and calcite, with minor amounts of calcium carbonate monohydrate, weddellite (and sometimes whewellite), struvite, amorphous material, and detrital silicates [13]. Crystallized urine from 14C-dated middens of pack rats from Utah and porcupines from New Mexico, USA and hyraxes from South Africa was dissolved in water, approximately one part

Immunospecificity of Fossil Proteins

The atomic structure of matter has been generally accepted by physicists and chemists for less than 100 years, and the molecular basis of genetics, the DNA double helix, has been understood only within the past half century. During recent decades, molecular evidence for the timing and topology of evolutionary relationships among bacteria, fungi, plants, and animals has been accumulating rapidly (Nei, 1987).