Ultra High Dilution Research Articles

Raman spectroscopy shows difference in drugs at ultra high dilution prepared with stepwise mechanical agitation

Abstract
 
 
 Objective
 
 
 The present study aims at deciphering the nature of the water structure in two drugs at ultra high dilution (HD) by Laser Raman Spectroscopy.
 
 
 Method
 
 Two drugs like Sulphur and Natrum mur and their three high dilutions 30cH, 200cH and 1000cH were selected for the study. The 30cH means dilution 1060 with mechanical agitation in 30 steps.Raman spectra of the drugs and their medium (90%ethanol)were obtained in the wave number region of 2600-3800 cm-1. The intensity ratio at vibration frequencies between 3220 and 3420 (R1) and that between 3620 and 3420 (R2) were calculated for each HD as well as the control.
 
 
 Results
 
 Raman spectra show differences in intensities in different HD’s and their control in the stretching vibrations of CH and OH groups. The three HD’s of each drug show inverse relationship with respect to the R1 values. However, for R2 the relationship of HD’s for each drug is positive.
 
 Conclusion
 
 R1 provides information about the relative number of OH groups with strong and weak hydrogen bonds. R2 suggests the relative number of OH groups with broken and weak hydrogen bonds. Judged from R1 values the lower is the rank of HD, the stronger is the H-bond of the OH groups. In the light of R2 values the higher is the HD rank the more abundant is the free OH groups. So, hydrogen bond strength and free OH groups together make an effective HD rank relating to Sulphur and Natrum mur.

Diluted versus potentitized probes of silver nitrate (10e-2 to 10e-10) and wheat germination

Corinne Kraus, Ute Knobloch, Scherer Waltraud, Peter Christian Endler
 Interuniversity College for Health and Development Graz / Castle of Seggau, Austria
 
 
 Background
 In 1926, an influence of a homeopathically prepared high dilution of silver nitrate on the growth of coleoptiles of wheat seedlings was described (Kolisko 1926). Later, in an extensive series of experiments, wheat was observed under the influence of extremely diluted agitated silver nitrate (10e-23, “24x”). Stalk lengths clearly indicate that development is enhanced by the probe silver nitrate 24x as compared to control (Scherer et al. 2015). A preliminary experiment was performed in early autumn 2015 on stalk growth of wheat seedlings treated with (not potentized) dilutions of silver nitrate 10e-6 to 10e-10 (“6e to 10e”), compared to potentized silver nitrate 6x to 10x (N = 100 per group). A clear, albeit not statistically significant trend was observed of 6x-stalks being longer (23.4 + 16.2 mm) than 6e-stalks (13.0 + 10.9 mm).
 
 Objective
 The aim of this study was to investigate the influence of diluted versus potentized low dilutions of silver nitrate (10e-2 to 10e-10) on wheat germination.
 
 Method
 The experiments were performed in late autumn 2015 on wheat grain (Triticum aestivum L., Capo variety). The grains were observed under the influence of aqueous solutions 10-2 to 10-10 part per weight of silver nitrate, either diluted in steps of 1 : 10 in distilled water by mere pipetting (probes “2e – 10e”), or diluted and agitated in steps of 1:10 (to create potentized probes “2x – 10x”). Untreated distilled water (“w”) served as an additional control. All probes were applied blindly. 100 grains were observed per treatment group in each of the groups resulting a total of 2,000 grains. Grains were placed in glass dishes, probes were added and dishes were covered with lids and placed in drawers . The following endpoint criteria were defined: K1 = visible emergence of sprout material, K2 = lifting of the operculum and emergence of the sprout and W1 = development of three roots. 
  
 
 Result
 Germination rates K1 of seedlings treated with “w”-probes (blue), with “e”-probes ranging from 2e to 10e (black) and with “x”-probes ranging from 2x to 10x (red) at the measuring points 20h, 24h and 28h (from left to right for each of the probes). 
 
 In K1, K2 and W, there is an obvious increase of germination rates from the high to the lower concentrations of silver nitrate, both in the “e” and in the “x”-groups and observable at 20h, 24h and 28h (p < 0.01). In contrast, germination rates of the two „w“-probes are practically alike (p > 0,05) 
 When “e” and “x”-data are compared, germination rates are higher under the influence of “x” than under the influence of “e” (p < 0.01 for the pooled “x”-values compared to the pooled “e”-values with regard to K1 as well as K2 as well as W). 
 
 Conclusion: A significant difference was found between wheat grains treated with mere dilutions compared to grains treated with potentised dilutions. 
 
 References
 1. Endler PC, Belavite P, Bonamin L,Jäger T, Mazon S. Replication of fundamental research models in ultra high dilutions 1994 and 2015 – update on a bibliometric study. Special issue Homeopathy London. 2015 a Oktober;104(4):234-45.
 2. Endler PC, Schulte J, Stock-Schroeer B, Stephen S. Ultra high Dilution 1994 revisited 2015 – the state of follow-up research. Special issue Homeopathy London. 2015 b Oktober;104(4):223-6.
 3. Kolisko L. Physiologischer Nachweis der Wirksamkeit kleinster Entitäten bei 7 Metallen – Wirkung von Licht und Pflanzen auf das Pflanzenwachstum. Dornach Schweiz: Philosophisch-Anthroposophischer Verlag am Goetheanum; 1926.
 4. Kraus C, Knobloch U. Diluted versus diluted and agitated probes of silver nitrate (10-2 to 10-10) and wheat germination, Thesis (MSc); branch campus UCN at Interuniversity College Graz / Schloss Seggau; 2016.
 5. Scherer-Pongratz W., Endler P.C., Lothaller H., Stephen S. Wheat and ultra high diluted silver nitrate – further experiments and re-analysis of data. Special issue Homeopathy London. 2015;104(4):246-9.

Drugs in ultra-high dilution induce changes in the enthalpy associated with loss of crystallization water in lactose

Drugs in ultra-high dilution (UHD) are used in homeopathy. Lactose is used as a binding medium for UHD drugs. FTIR and Raman spectroscopy revealed that although devoid of molecules of the starting substance, different UHD drugs exhibit different amounts of free water molecules and variation in hydrogen bond strength. The aim of the present study was to establish whether specific water structures in UHD could specifically modify the water structure in lactose, particularly the water of crystallization. 3 UHD’s (potencies), 30cH, 200cH and 1000cH, of 2 drugs, Natrum muriaticum and Sulphur were mixed to lactose samples separately. Differential scanning calorimetry (DSC) of the samples was measured. The thermograms of potencies mixed to lactose differed from each other with respect to temperature and enthalpy associated with the removal of water of crystallization from lactose. We believe that the tested UHD modified the water structure in lactose thereby changing the enthalpy for the removal of water of crystallization. Different levels of thermal energy are needed to remove both free water molecules and water of crystallization from lactose. UHD’s also contributed to the change in enthalpy associated with the removal of water of crystallization from lactose. The tested UHD might have modified the number and strength of hydrogen bonds in the crystal structure of lactose. Specific water structures in liquid aqueous ethanol medium are transferable to the solid medium(lactose).

Promotion of Growth, Chlorophyll Content and Yield of Rice by a New Drug at Ultra High Dilution

Application of synthetic fertilizers reduces natural fertility of soil and contaminates ground water. Some photosynthesis inhibitors at ultra-high dilution (UHD) increase photosynthesis, growth and yield of crops. A weedicide Paraquat at UHD enhanced growth and yield of potatoes in fields. This weedicide was serially diluted with distilled water and manually succussed in 30 steps following the method of preparation of homeopathic dilutions called potencies. In this way the 30th potency of Paraquat called Paraquat 30cH was prepared and preserved in 90 % ethanol. Paraquat 30cH was diluted with water 1:1000 (v/v) and sprayed on rice plants in a field measuring 0.3125 acre. The control plot of the same area was situated 300 meters away from the test plot. Three treatments were given at an interval of 7 days. Treated plot showed increased growth, chlorophyll content and yield of rice significantly as compared to control. The UHD of the weedicide produced exactly the opposite effect of the crude material on plants. The increased growth and yield of rice by Paraquat 30cH may be due to enhancement of photosynthesis of treated plants. The UHD of Paraquat increased yield of rice by 19.35% over the control.

Extreme dilutions of mercuric chloride produce longer binding interaction with ?-amylase as compared to blank solvents

Background
 High and ultra low doses of HgCl2 modulate ?-amylase starch interaction through two different binding sites of the enzyme. Mercurius corrosivus at ultra high dilution (UHD) is reported to have a long duration of action for 30-60 days.
 Objectives
 (i) To see whether the mother tincture and UHDs of mercuric chloride could directly act on ?-amylase without intervention of its substrate starch. (ii) To see whether the MT and UHDs produce longer binding interaction with ?-amylase than the control.
 Methods
 Mercuric chloride MT (0.15 M) or Merc cor ? and its three UHDs, 30, 200, 1000 cH called potencies were in 90% ethanol. Blank 90% ethanol and deionised and distilled (DD) water were used as controls. All ethanol based ligands were diluted with DD water to reduce EtOH content to 0.09%. Using an ITC instrument each ligand was injected once at 10 µl into15µM ?-amylase at 25 0C and the reaction was observed for 2000 s. 
 Results
 While Merc cor ? produced endothermic reaction, all other ligands did exothermic reaction. Water control and blank ethanol maintained post injection heat change up to 1200 sec. All other ligands sustained heat change for the entire period of observation (2000 sec). 
 Conclusions
 Merc cor ? and potencies produced exactly the opposite reaction at the protein binding sites. The reaction was short-lived with water control and blank ethanol, but prolonged with Merc cor ? and potencies. Merc cor 200 cH and 1000 cH produced highest heat change (6 µl/sec) during interaction with ?-amylase.

Ultra High Dilution of Zinc in the Management of Refractory Parkinson’s Disease-A Case Report

Ultra High Dilution of Zinc in the Management of Refractory Parkinson’s Disease-A Case Report

Ultra High Dilution of Zinc in the Management of Refractory Parkinson’s Disease-A Case Report

Ultra High Dilution of Zinc in the Management of Refractory Parkinson’s Disease-A Case Report

Piezoelectric and dielectric properties of Bi3TiNbO9 prepared by hot pressing from powders activated using the serial dilution method

Bi-based layer structure ferroelectrics are the most promising compounds for the fabrication of high-temperature piezoelectric materials. Studies aiming to develop and optimize the techniques to produce efficient high-density piezoelectric ceramics, and to investigate the effects of ceramics production conditions on their structure and functional properties, have become high-priority objectives of modern piezo-engineering. We applied ultra high dilution (UHD) technology to pre-treat Bi3TiNbO9 powders and used hot pressing to prepare perovskite-layer structured ceramic specimens. Main characteristics of the synthesized piezoelectric ceramic specimens (the dimensions of the Bi3TiNbO9 orthorhombic unit cell, dielectric permittivity, dielectric loss, piezoelectric coefficient d33 and pyroelectric coefficient pσ) and their temperature-dependent variations were studied using piezoelectric, dielectric, and pyroelectric measurements. X-ray diffraction studies demonstrated that the prepared ceramics were single phased, and highly textured, as their plate-like crystallites were preferentially aligned perpendicularly to the pressure axis on hot pressing. For d33, an increase in values of more than 20% was found for samples obtained using a combined modification of the UHD technology and hot pressing (12 pC/N) relative to intact samples, and more than two times relative to unmodified Bi3TiNbO9 ceramics (6 pC/N). Due to their characteristics, the obtained ceramics are promising materials for high-temperature applications; of particular interest is potential use, as electroacoustic transducers and sensors for operation at high temperatures. Thus, the UHD technology can modify the properties of ceramics and is relatively easy to implement. This makes it attractive for use in various fields of science and technology.

Substitution therapy with amphetamine-isotherapic attenuates amphetamine toxicological aspects of addiction

Introductionamphetamine (AMPH) is related to development of addiction, anxiety-like behaviors and impairments of memory after chronic use. In the current experiment, an ultra-high dilution (10−24mg/mL) of AMPH was used, consisting of the AMPH isotherapic (AMPH-ISO), which can be used as a replacement therapy to treat AMPH addiction. AimTo verify the influence of AMPH-ISO on toxicological aspects of AMPH addiction. MethodsRats received d,l-AMPH (4.0 mg/kg, i.p.) in the conditioned place preference (CPP) paradigm (8 days). Then, half of each experimental group (AMPH or saline) received AMPH-ISO/vehicle (0.2 mL per rat, once a day), for fourteen days. On the fifteenth day, animals were re-assessed in the CPP paradigm (to verify relapse behaviors) after a single dose of AMPH (2.0 mg/kg). Subsequently, anxiety-like behaviors were quantified, followed by ex vivo assays in the pre-frontal cortex. ResultsAMPH-ISO prevented relapse-like behavior of AMPH and reduced anxiety-like behavior per se in animals co-treated with AMPH. Molecular analysis evidenced that AMPH-ISO modulated dopaminergic targets (dopamine transporter, tyrosine hydroxylase and D1-R), whose immunoreactivity was increased by AMPH. Also, AMPH-ISO increased catalase activity and NPSH levels and reduced lipid peroxidation and protein carbonyl levels in the prefrontal cortex. ConclusionThis study shows that an ultra-high dilution of AMPH may be a useful alternative which can contribute with AMPH addiction treatment.

A novel approach of Homeopathy, Alternative to antibiotics

Homeopathic system of medicine is globally used alternative system of medicine. It is becoming popular worldwide. However homeopathic system of medicine has to face many criticisms due to presence of ultrahigh dilution. In developed countries where there is much advancement are present in the field of medicine where it is a big problem that microbes are becoming resistant and it is the need of the time to introduce the alternative approach to kill the microbes with minimal side effects. Homeopathic system of medicine contains ultra-high dilution that kills the microbes with minimal side effects.

65 Inactivation Kinetics of Epizootic Hemorrhagic Disease Virus (EHDV) By Ingredients Contained in Expect Healthy Deer Technology®.

Expect Healthy Deer Technology® is a novel feed additive that contains natural feed ingredients that are known to have anti-viral, anti-bacterial, and anti-fungal properties. Epizootic Hemorrhagic Disease (EHD), caused by EHD virus (EHDV), is a hemorrhagic disease spread by small biting midge gnats affecting certain species of animals, especially deer, although it can also affect elk and cattle. Death losses in deer from EHDV are very high, and in localized outbreaks, it can wipe out a large percentage of a deer herd. The aim of this study was to evaluate the virucidal effectiveness of a key ingredient contained in Expect Health Deer Technology® against EHDV. Briefly, serial dilutions of the key ingredient were mixed with equal amounts of EHDV. Samples were removed after various periods of contact and tested for the amount of surviving virus by inoculation in baby hamster kidney cells (BHK-21), which can support infection by EHDV. Serotype 1 of EHDV (EHDV-1) was obtained from the National Veterinary Services Laboratories, Ames, IA. To determine virucidal activity, titer levels of EHDV were calculated in triplicate for each dilution of the ingredient. The initial virus titer for the EHDV-1 was 3.50 log10 TCID50/0.1 ml. At the low dilution rate (1:2 dilution), the ingredient killed (P < 0.05) 3 logs (99.9%) of virus within 2 h and killed (P < 0.05) 2.5 logs at 12 and 24 h. At a medium dilution rate (1:20) the ingredient killed (P < 0.05) 3 logs (99.9%) of the EHD virus after 2 h, but killed (P < 0.05) 2.5 logs after 12 and 24 hours. At the high dilution rate (1:200) the ingredient killed (P < 0.05) 3 logs (99.9%) of virus after 2 h, but killed (P < 0.05) 2.5 logs after 12 and 24 h. At ultra-high dilution rates (1:2,000 and 1:20,000) the ingredient was less effective. In summary, the ingredient within Expect Healthy Deer Technology® demonstrated strong virucidal activity against EHDV under in-vitro (laboratory) conditions.

A new high temperature reactor for operando XAS: Application for the dry reforming of methane over Ni/ZrO2 catalyst.

The construction of a high-temperature reaction cell for operando X-ray absorption spectroscopy characterization is reported. A dedicated cell was designed to operate as a plug-flow reactor using powder samples requiring gas flow and thermal treatment at high temperatures. The cell was successfully used in the reaction of dry reforming of methane (DRM). We present X-ray absorption results in the fluorescence detection mode on a 0.4 wt. % Ni/ZrO2 catalyst under realistic conditions at 750 °C, reproducing the conditions used for a conventional dynamic microreactor for the DRM reaction. The setup includes a gas distribution system that can be fully remotely operated. The reaction cell offers the possibility of transmission and fluorescence detection modes. The complete setup dedicated to the study of catalysts is permanently installed on the Collaborating Research Groups French Absorption spectroscopy beamline in Material and Environmental sciences (CRG-FAME) and French Absorption spectroscopy beamline in Material and Environmental sciences at Ultra-High Dilution (FAME-UHD) beamlines (BM30B and BM16) at the European Synchrotron Radiation Facility in Grenoble, France.

Preliminary Study on Force-Like Effects between As45x, Water, and Wheat Seeds Performed by Means of the Droplet Evaporation Method

Background: The droplet evaporation method (DEM) is based on pattern formation in evaporating droplets. It has been shown that the local connected fractal dimension (LCFD; a complexity measure) of crystalline structures grown in evaporating droplets of wheat seed leakages depended upon whether the seeds were treated with an ultra-high dilution (UHD) or water control.1, 2 In homeopathy it is usually assumed, that UHD’s need to come in direct (physical) contact with the organism to be treated to exhibit their action; however, recently, it has been demonstrated on a wheat seed germination model that UHD’s may influence organisms also at a distance, i.e. without any physical contact. 3 In this case the UHD's effectiveness decreases with increasing distance. Here we test whether DEM might serve also as a tool to study such force-like influences. In a series of three DEM experiments (E1-3) we studied (i) force-like effects occurring between As2O3 45x treatment (As45x) and undiluted, unsuccussed, ultrapure water (W), (ii) As45x and wheat seeds, as also (iii) whether force-like effects may be shielded by means of aluminum foil, commonly applied for such purposes in homeopathic research.

Pilot study on ultra high dilution of physostigma venenosum for accommodation error-myopia

Pilot study on ultra high dilution of physostigma venenosum for accommodation error-myopia

High energy-resolution x-ray spectroscopy at ultra-high dilution with spherically bent crystal analyzers of 0.5 m radius.

We present the development, manufacturing, and performance of spherically bent crystal analyzers (SBCAs) of 100 mm diameter and 0.5 m bending radius. The elastic strain in the crystal wafer is partially released by a "strip-bent" method where the crystal wafer is cut into strips prior to the bending and the anodic bonding process. Compared to standard 1 m SBCAs, a gain in intensity is obtained without loss of energy resolution. The gain ranges between 2.5 and 4.5, depending on the experimental conditions and the width of the emission line measured. This reduces the acquisition times required to perform high energy-resolution x-ray absorption and emission spectroscopy on ultra-dilute species, accessing concentrations of the element of interest down to, or below, the ppm (ng/mg) level.

Main-chain degradable single-chain cyclized polymers as gene delivery vectors

Single-chain technology (SCT) allows the manipulation of polymeric architectures at an individual polymer chain level, providing a new platform for the fabrication of nanoscale polymeric objects. However, it remains problematic to apply this newborn technology to the biological and medical fields, since synthesis of single-chain polymeric nanoparticles relies heavily on controlled/living radical polymerization of vinyl based monomers, yielding a persistent non-degradable carbon-carbon based backbone. Moreover, the ultrahigh dilution conditions often required for single-chain polymer nanoparticle synthesis limits large-scale applicability. A versatile approach to achieve backbone degradability in single-chain cyclized polymers was developed by combining ring-opening addition polymerization and intramolecular cyclization into a one-pot RAFT copolymerization of cyclic and mono/multi-vinyl monomers system under concentrated conditions. The in situ intramolecular cyclization of individual propagating chains was achieved by kinetic control and statistical manipulation of mono- and multi-vinyl monomer copolymerization. The cyclic allylsulfide monomer 3-methylidene-1,9-dioxa-5,12,13-trithiacyclopentadecane-2,8-dione (MDTD) was copolymerized via the ring-opening pathway to introduce disulfide groups into the vinyl-based backbone without compromising the single chain propagation nature. Backbone degradable single chain polymeric nanoparticles were obtained with molecular weights of 10kDa and MDTD incorporation ratios of 4.7%. Chemical degradation of the nanoparticles confirmed both their single chain nature, as well as backbone degradability. The single-chain cyclized polymeric nanoparticles were evaluated for their gene transfection capabilities. The backbone degradable nanoparticles displayed high transfection efficiencies and low cytotoxicities in both 3T3 and HeLa cells.

Accurate Measurement of the in vivo Ammonium Concentration in Saccharomyces cerevisiae

Ammonium (NH4+) is the most common N-source for yeast fermentations, and N-limitation is frequently applied to reduce growth and increase product yields. While there is significant molecular knowledge on NH4+ transport and assimilation, there have been few attempts to measure the in vivo concentration of this metabolite. In this article, we present a sensitive and accurate analytical method to quantify the in vivo intracellular ammonium concentration in Saccharomyces cerevisiae based on standard rapid sampling and metabolomics techniques. The method validation experiments required the development of a proper sample processing protocol to minimize ammonium production/consumption during biomass extraction by assessing the impact of amino acid degradation—an element that is often overlooked. The resulting cold chloroform metabolite extraction method, together with quantification using ultra high performance liquid chromatography-isotope dilution mass spectrometry (UHPLC-IDMS), was not only more sensitive than most of the existing methods but also more accurate than methods that use electrodes, enzymatic reactions, or boiling water or boiling ethanol biomass extraction because it minimized ammonium consumption/production during sampling processing and interference from other metabolites in the quantification of intracellular ammonium. Finally, our validation experiments showed that other metabolites such as pyruvate or 2-oxoglutarate (αKG) need to be extracted with cold chloroform to avoid measurements being biased by the degradation of other metabolites (e.g., amino acids).

Highly stable polyglutamate derivatives/siRNA polyplex efficiently down-relegate survivin expression and augment the efficacy of cisplatin

RNA interfere (RNAi)-based technology holds great promise in cancer treatment. The use of small interfering RNA (siRNA), however, is hampered by its low delivery efficiency in vivo when they are diluted in blood biofluids and in the presence of serum and salt. In this study, we developed the polyglutamate derivative polymer brush, poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (mPEG-b-PG-g-spermine, PPGS), which could efficiently deliver survivin-siRNA under ultra-high dilution and in the presence of salt (NaCl 150mM) and serum (10% FBS), most likely due to its PEG-shelled polymer brush structure. On the contrary, aggregation occurred when PEI/siRNA polyplex dispersed in saline and serum-containing media and PEI polyplex dissociated after making a 256-fold dilution. PPGS/si-survivin polyplex exhibited high cellular uptake efficiency and efficiently down-regulated the expression of survivin mRNA in the cisplatin-resistance of non-small cell human lung adenocarcinoma (A549/DDP) cells in the presence of serum. However, either PEI polyplex or Lipofectmine 2000 complex was unstable in serum and salt-containing media and at high dilution rates, which resulted in their dramatical decrease of cellular uptake and gene-silencing efficiency in these conditions. The PPGS/si-survivin polyplex also exhibited synergistic effects of killing the cancer cells by combination treatment with cisplatin. Therefore, the PPGS gene carrier showed great potential in systemic siRNA delivery, and its combination with chemotherapeutic drug is promising in treating drug resistant cancers.

Update on preliminary elements of a theory of ultra high dilutions

The different mechanisms: A. of the interaction between the molecular mother substance and the solvent water or ethanol B. of the storage of molecule-specific information in the solvent. C. the physiological basis of the sensitivity of the living organism towards an ultra high dilution (UHD). D. the mechanism of the interaction of the test dilution with the organism are largely unknown. Several ideas have been postulated, and experiments to test them carried out in physics and in biology. The authors revisited a 1994 contribution on 'preliminary elements of a theory on UHDs' and updated it with regard to more recent literature and research findings. Although the experimental basis can still be questioned in most cases, remarkable fundamental observations have been made to explain the effects of UHDs. For some topics in question, it appears that information specific properties of the diluted substance to be transferred is stored by means electromagnetic fields. The interaction between the UHD and the organism seems to be electromagnetic in nature. The transmission of information from (bio-)molecules to the UHD is of special interest. Again, electromagnetic actions and vector potential fields appear to be implicated. The mechanisms of information storage and transfer in UHDs are far from fully understood, but progress has been made at experimental and theoretical levels.

“Ultra High Dilution 1994” revisited 2015 – the state of follow-up research

The "Ultra High Dilution 1994" project was an endeavour to take stock of the findings and theories on homeopathic extreme dilutions that were under research at the time in areas of biology, biophysics, physics and medicine. The project finally materialized into an anthology assembling contributions of leading scientists in the field. Over the following two decades, it became widely quoted within the homeopathic community and also known in other research communities. The aim of the present project was to re-visit and review the 1994 studies from the perspective of 2015. The original authors from 1994 or close laboratory colleagues were asked to contribute papers covering their research efforts and learnings in the period from 1994 up to 2015. These contributions were edited and cross-referenced, and a selection of further contributions was added. About a dozen contributions reported on follow-up experiments and studies, including further developments in theory. Only few of the models that had seemed promising in 1994 had not been followed up later. Most models presented in the original publication had meanwhile been submitted to intra-laboratory, multicentre or independent scrutiny. The results of the follow-up research seemed to have rewarded the efforts. Furthermore, contributions were provided on new models that had been inspired by the original ones or that may be candidates for further in-depth ultra high dilution (UHD) research. The project "Ultra High Dilution 1994 revisited 2015" is the latest output of what might be considered the "buena vista social club" of homeopathy research. However, it presents new developments and results of the older, established experimental models as well as a general survey of the state of UHD research.