Use Of Saponin Research Articles

Effect of Saponin on Methylene Blue (MB) Photo-Antimicrobial Activity Against Planktonic and Biofilm Form of Bacteria.

Bacterial resistance has led to the spread of bacterial infections such as chronic wound infections. Finding solutions for combating resistant bacteria in chronic wounds such as Staphylococcus aureus and Pseudomonas aeruginosa became an attractive theme among researchers. P. aeruginosa is a gram negative opportunistic human pathogenic bacterium that is difficult to treat due to its high resistance to antibiotics. S. aureus (gram negative bacterium) also has a high antibiotic resistance, so that it is resistant to vancomycin (VRSA), tetracycline, fluoroquinolones and beta-lactam antibiotics including penicillin and methicillin (MRSA). In particular, S. aureus and P. aeruginosa have intrinsic and acquired antibiotic resistance, making the clinical management of infection a real challenge, especially in patients with comorbidities. aPDT can be proposed as a new method in the treatment of multi-drug resistant bacteria in chronic wound infection conditions. In this study, the effect of saponin (100 μg/mL) on photodynamic inactivation on planktonic and biofilm forms of P. aeruginosa (ATCC 27853) and S. aureus (ATCC 25923) strains and on Human Dermal Fibroblast (HDF) cells was investigated. Methylene blue (MB) was used as photosensitizer (0, 10, 50, 100 μg/mL). The light source was a red LED source (660 nm; power density: 20 mW/cm2) which is related to the maximum absorption of MB. The results showed that the use of saponin in combination with MB-aPDT (Methylene Blue-antibacterial photodynamic therapy) reduces the phototoxic activity of MB due to decreasing the monomer form of MB. This result was obtained by spectrophotometric study. Also, the result of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay showed that 8 min of irradiation (660 nm)at 10 μg/mL concentration of alone MB had the lowest phototoxic effect on HDF cells. Due to reduced phototoxic properties of MB in this method, detergents containing saponins not recommended to applied at the same time with MB-aPDT in wound infection area.

The Effectiveness of Using a Combination of Saponin and Vaccine Given In Ovo on Hatchability and Early Growth Performance of Local Chickens

A study has been carried out to determine the correct dosage for using a combination of saponin and vaccine in an in ovo formula on hatchability and early growth performance. There were four levels of saponin use (0.0; 1.5; 3.0; 4.5 microgram) arranged using a factorial design with two factors, namely saponin level as the first factor, while whether or not vaccine was used as the second factor, so there were eight formula combinations. Each formula combination was dissolved in phosphate buffered saline, then injected into the amnion of fertile eggs of Sentul chickens during incubation for 18 days (0.5 ml/egg) using an automatic injector machine with a 20G needle. The results showed that increasing saponin levels combined with vaccines as an ingredient in the in ovo feeding formula results in decreased hatchability. A very significant decrease occurred at the 4.5 µg level. The average hatchability of vaccine treatment was significantly better than those treated without vaccine. There is no interaction effect of the two materials on hatchability. However, the interaction effect was seen in all parameters of early growth performance of Sentul chicken during the 4 weeks of observation. The vaccine treatment will be more effective if it is used separately or not mixed with saponin (0.0 µg), while the use of saponin without vaccine will produce the best weight gain and feed efficiency when used at the highest dose level (4.5 µg).

Eco-friendly surfactants in glyphosate formulation

Weeds affect various crops worldwide, causing low yields and, therefore, significant economic losses. These losses can be minimized by the use of herbicides such as glyphosate. However, the efficiency of glyphosate depends on the type of agrochemical formulations. The most widely used surfactant is polyethoxylated tallow amine. Nevertheless, the disadvantage of these compounds is that their toxicity is greater than that of glyphosate itself. Thus, this study aimed to develop an environmentally-friendly combination of surfactants that can increase the performance of glyphosate compared to other currently used formulations. Saponin (S) is environmentally friendly and has a unique ability to go through the waxy cuticle of the weed leaf. However, its interfacial properties are very poor. In contrast, the alkyl glucoside (AG) mixture has shown excellent interfacial properties, being an environmentally safe surfactant, but cannot pass through the cuticle. In the present study, we mixed both surfactants. Two formulations were made with 20% (F1) and 2% (F2) of S with 4% AG. To verify the usefulness of our formulations, they were compared against a commercial product. The results showed that the commercial product had better CMC 0.3±0.1% and pC20 1.155±0.099 than our formulations F1 and F2. Formulations F1 and F2 showed better gCMC than the commercial product 36.5±4.1 mN/m and 30.9±1.4 mN/m, respectively. Field tests showed that F2 was more effective than the commercial product in eliminating weeds at the end of the test at 30 days. Our results allowed confirming that the use of saponin improves the efficiency of glyphosate. The work showed that structures similar to cyclopentaneperhydrophenanthrene are very effective for introducing drugs into plants through the leaves. This is an advance in general and in particular for the increase of the yield in certain crops.

Improvement of Renewable Bioenergy Production in Microbial Fuel Cells with Saponin Supplementation

Microbial fuel cell (MFC) is one of renewable biofuel production technology that directly converts biomass to electricity. Cellulosic biomass is particularly attractive renewable resources for its low cost and abundance and neutral carbon balance. However, methanogenesis remains as a major factor limiting MFC performance. The current study reports that saponin addition at 0.05% w/v dose to anolyte in MFCs inhibited methanogenesis and improves power generation and cellulose fermentation. Mediator-less two chamber H-type MFCs were prepared using rumen fluid as anode inocula at 20% v/v of anolyte to convert finely ground pine tree (Avicel) at 2%, w/v to electricity. Saponin was added to the anode of MFC at 0.005% or 0.05% v/v dosage for treatment. MFC power and current across an external resistor were measured daily for 10d. On d10, collected gases from anode compartment were measured for total gas volume and analyzed for gas composition on gas chromatography. Supplementation of saponin to MFC at 0.005% did not have any effects on electricity generation or biogas production and composition. Saponin at 0.05% dose reduced 10% of methane production and increased 40% of CO2 production and 6.4% of total gas production for 10d MFC operation. Voltage across resistor prior to treatment addition (d0) was 164.75 ± 9.07 mV. In control group, voltage across resistor did not change (P = 0.9153) with time course and mean was 167.8 ± 8.20 mV ranged from 157 to 174.5 mV during 10d operation. In 0.05% Saponin group, voltage across resistor increased (P 0.0001) after d2 and mean was 187.3 ± 4.30 mV ranged between 161.5 and 204.0 mV and the 10d mean of voltage across resistor in 0.05% Saponin was greater (P 0.0001) than in control group. 0.05% Saponin also had greater voltage across resistor at d5 (P = 0.0030) and d6 (P = 0.0246) than control. End point potential increased (P 0.0001) in 0.05% Saponin after d2. 0.05% Saponin had greater (P 0.0001) in 0.05% Saponin. Power density increased (P 0.0001) after d2 in 0.05% Saponin. 0.05% Saponin MFCs had greater (P 0.0001) overall mean of 10d operation. The current study provides strong background for potential use of saponin and saponin containing natural resources for methanogenesis inhibitor and cellulolysis enhancer in MFC and also cellulolysis reactors.

An experimental investigation on the use of saponin as a non-ionic surfactant for chemical enhanced oil recovery (EOR) in sandstone and carbonate oil reservoirs: IFT, wettability alteration, and oil recovery

Surfactant flooding, a chemical enhanced oil recovery (EOR) technique, boosts oil production mainly through lowering oil–water interfacial tension (IFT) and altering reservoir rock wettability. In the current study, the performance of pure saponin, a non-ionic surfactant, was evaluated for EOR in sandstone and carbonate reservoirs. The performance evaluation experiments were IFT by pendant drop method, wettability through the use of sessile drop technique, and core flood to discover the oil recovery improvement. According to IFT experiments, the surfactant had a critical micelle concentration (CMC) of 5g/L, and which it decreased the oil–water IFT by 66.98% at CMC, for the system free from salt. Moreover, after increasing the salinity by sodium chloride up to 100g/L, it not only was salt-tolerant but also lowered oil–water IFT up to 77.31%. Depending on salt concentration, the surfactant decreased the sessile drop contact angle by 4.49–27.84° and 5.62–16.98° for the sandstone and carbonate slices, respectively. From the core flood experiments, the oil recovery was improved by 8.4% and 6.23% for the surfactant flooding in the sandstone and carbonate cores, respectively. All in all, the non-ionic surfactant saponin performed best in improving oil recovery from both sandstone and carbonate reservoirs.

Effects of saponin capped triangular silver nanocrystals on the germination of Pisum sativum, Cicer arietinum, Vigna radiata seeds & their subsequent growth study.

In this study, saponin capped triangular silver nanocrystals have been synthesised using fenugreek seed extract, where the extract acts both as a reducing and capping agent. X-ray diffraction study confirms the purity and crystalline nature of the prepared nanocrystals and transmission electron microscopic study shows the triangular morphology with the average edge length of 72 nm, along with the atomic force microscopy study for the height or the width of the triangular nanocrystals. These nanocrystals have been investigated against a few pulses (seeds) such as Pisum sativum, Cicer arietinum and Vigna radiata for their effect on the germination as well as growth of root and shoot. Considering different concentration of silver nanocrystals solution, it has been found that 25 × 10-4 and 80 × 10-4 μg/ml are the minimum and maximum concentrations of silver nanocrystals, within this range, germination and subsequent growth of root and shoot are effective. The result shows significant positive influence on the growth of root and shoot of all seeds in comparison to those of unexposed control germination. Therefore, the result of this experiment has confirmed that the use of saponin capped silver nanocrystals enhances the germination and growth of plants.

Saponin seed priming improves salt tolerance in quinoa

AbstractQuinoa (Chenopodium quinoa Willd.) is a facultative halophyte of great value, and World Health Organization has selected this crop, which may assure future food and nutritional security under changing climate scenarios. However, germination is the main critical stage of quinoa plant phenology affected by salinity. Therefore, two experiments were conducted to improve its performance under salinity by use of saponin seed priming. Seeds of cv. Titicaca were primed in seven different solutions with varying saponin concentrations (i.e. 0%, 0.5%, 2%, 5%, 10%, 15%, 25% and 35%), and then, performances of primed seeds were evaluated based on mean germination time and final germination percentage in germination assays (0 and 400 mM NaCl stress). Saponin solutions of 10%, 15% and 25% concentration were found most effective priming tools for alleviating adverse effects of salt stress during seed germination. Performances of these primed seeds were further evaluated in pot study. At six‐leaf stage, plants were irrigated with saline water having either 0 or 400 mM NaCl. The results indicated that saline irrigation significantly decreased the growth, physiology and yield of quinoa, whereas saponin priming found operative in mitigating the negative effects of salt stress. Improved growth, physiology and yield performance were linked with low ABA concentration, better plant water (osmotic and water potential) and gas relations (leaf photosynthetic rate, stomatal conductance), low Na+ and high K+ contents in leaves. Our results suggest that saponin priming could be used as an easy‐operated and cost‐effective technology for sustaining quinoa crop growth on salt‐affected soils.

Production of Saponin Biosurfactant from Glycyrrhiza glabra as an Agent for Upgrading Heavy Crude Oil

AbstractSaponins are the main group of phytogenic biosurfactants extracted from plants. One of the significant applications of these compounds is upgrading and viscosity reduction of heavy crude oil water in oil (W/O) emulsions. In this research, use of saponin extracted from Glycyrrhiza glabra was investigated for viscosity reduction of heavy crude oil and upgrading its API properties. The extracted saponin was characterized using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Phase behavior analysis demonstrated a reduction in initial viscosity and improved API gravity of the heavy oil from 2350 mPa·s and 19 to 900 mPa·s and 27, respectively. In addition, the emulsification index (E24) was found to be 98 % at a saponin concentration of 8 % w/v. It was observed that the emulsions were stable in the pH range of 5.5–13, temperature from 30 to 80 °C and salinity up to 6 % w/v of NaCl solution. Average diameter of W/O droplets evaluated by dynamic light scattering (DLS) were in the range of 10–15 µm. The results obtained from the present research revealed that the extracted saponin improved the physical characteristics of heavy crude oil. We propose the use of saponin as a potential alternative to conventional emulsifiers for upgrading heavy crude oil in petroleum industry.

Investigation of the adsorption/desorption equilibria of Cd(II), Zn(II) and Cu(II) ions on/from immobilized digested sludge using biosurfactants

The study investigated the adsorption characteristic of Cd(II), Zn(II) and Cu(II) ions and their mixture on activated sludge immobilized in 1.5 % sodium alginate with 0.5 % polyvinyl alcohol (ASAA), and the desorption of these metal ions from biosorbent using biosurfactants (saponin and JBR 515) and HNO3. Cadmium, zinc and copper were most effectively adsorbed by the immobilized sludge in a pH range of 5.0–6.0. Desorption of metals with saponin was the most effective at pH 1–5, with rhamnolipid JBR 515—at pH 5–6 and with HNO3 at pH 2.0. The results of adsorption and desorption were presented with the use of Freundlich, Langmuir, Redlich–Peterson, Sips and a double Langmuir adsorption isotherm equations. The coefficient of determination R 2 and the average relative error were used to evaluate whether the models fit to experimental data. The best fit of the adsorption isotherm equation to experimental data was demonstrated for the double Langmuir isotherm. The highest adsorption capacity from solutions containing single metals was obtained for Cd (108.83 mg/g dm). For solutions containing metal mixture, the highest adsorption capacity (37.21 mg/g dm) was obtained for Cu. The highest desorption of single metals was received with the use of saponin and HNO3 (over 90 %). Biosurfactants were shown to be the most effective in leaching of metals from their mixture. The desorption efficiency of saponin for each metal was over 99 %.

QS-21 enhances the early antibody response to oil adjuvant foot-and-mouth disease vaccine in cattle.

PurposeOne of the most important tools against foot-and-mouth disease, a highly contagious and variable viral disease of cloven-hoofed animals, is vaccination. However, the effectiveness of foot-and-mouth disease vaccines on slowing the spread of the disease is questionable. In contrast, high potency vaccines providing early protection may solve issues with the spread of the disease, escaping mutants, and persistency. To increase the potency of the vaccine, additives such as saponin and aluminium hydroxide are used. However, the use of saponin with an oil adjuvant is not common and is sometimes linked to toxicity. QS-21, which is less toxic than Quil A, has been presented as an alternative for use with saponin. In this study, the addition of QS-21 to a commercially available foot-and-mouth disease water-in-oil-in-water emulsion vaccine was evaluated in cattle.Materials and MethodsAfter vaccination, serum samples were collected periodically over 3 months. Sera of the QS-21 and normal oil vaccine groups were compared via serum virus neutralization antibody titre and liquid phase blocking enzyme-linked immunosorbent assay antibody titre.ResultsThe results showed that there was a significant early antibody increase in the QS-21 group.ConclusionStrong early virus neutralizing antibody response will be useful for emergency or ring vaccinations against foot-and-mouth disease in target animals.

Effect of Organized Assemblies. Part 4. Formulation of Highly Concentrated Coal−Water Slurry Using a Natural Surfactant

Coal−water slurry has received considerable research nowadays due to its ability in substituting energy sources. The present work reports the formulation of highly concentrated coal−water slurry using a natural occurring surface active compound, saponin, extracted from the fruits of plant Sapindous laurifolia. The isolation of saponin from the plant and its surface activity has been discussed. The rhelogical characteristics of coal−water slurry have been investigated as a function of coal loading, ash content of coal, pH, temperature, and amount of saponin. The viscosity of the slurry and zeta potential are substantially decreased with concomitant shift of the isoelectric point of coal on adsorption of saponin to it. In the presence of 0.8% of saponin, coal−water slurry containing 64% weight fraction of coal could be achieved. The slurry is stable for a period of as long as 1 month in contrast to 4−5 h in the case of bare coal−water slurry. The results confirm the use of saponin as a suitable additive for...

Utilização de saponina em citometria de fluxo: uma alternativa factível para permeabilização celular

A pesquisa de antígenos intracelulares por citometria de fluxo é essencial para o estudo imunofenotípico das doenças onco-hematológicas. A utilização de saponina para permeabilização celular tem se mostrado eficaz e de menor custo. Com suas propriedades detergentes, permeabiliza a membrana citoplasmática sem danificá-la ou alterar a expressão dos antígenos de membrana, permitindo a detecção simultânea de antígenos intracelulares e de superfície. O objetivo deste trabalho foi analisar a eficácia da técnica de permeabilização celular com a utilização de saponina como agente permeabilizante. Foram avaliadas 36 amostras de sangue periférico e de medula óssea enviadas ao Laboratório de Imunopatologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo para estudo imunofenotípico. Realizamos a técnica de imunofluorescência direta e utilizamos o programa CellQuest (Becton Dickinson, San Jose, CA) do citômetro de fluxo FACSCalibur (Becton Dickinson, San Jose, CA) para aquisição e análise dos dados. Observamos excesso de perda celular quando utilizamos o tampão de lavagem estocado por período superior a sete dias, à temperatura de 2ºC a 8ºC, e perda mínima com tampão de lavagem recém-preparado ou congelado no momento do preparo e descongelado apenas no momento do uso. Para eliminar o excesso de perda celular realizamos análise sistemática das etapas da técnica, o que nos permitiu adequá-la e utilizá-la na rotina de nosso laboratório. Em país de recursos escassos padronizamos uma técnica viável para pesquisar antígenos intracelulares por citometria de fluxo, mais rápida, eficaz e com redução dos custos financeiros em 35%.

Validation of immunity induced by inactivated CCPP vaccine with different adjuvants

The study was conducted in the premises National Veterinary Institute (NVI) to validate the immunity induced by inactivated F38 antigen adjuvated with saponin and Montanide ISA 50 and combined with and without anthrax vaccine. Post-inoculation reactions; pyrogenic effects, safety and inocuity of the vaccines were assessed. Increased body temperature and local edematous reactions were seen in animals inoculated with saponin adjuvated CCPP vaccine (100%) while 20% of the goats in ISA 50 adjuvated group showed local reaction. Sera collected from day 0 to 10th week were tested to assess the sero-conversion using monoclonal antibody based B-ELISA technique. Saponin adjuvated groups, in both monovalent CCPP and in the combined CCPP with anthrax vaccine showed a higher mean percentage of inhibition value as compared with ISA 50 adjuvated vaccine. After 8 months of post vaccination, contact challenge trial was conducted in 66 experimentally vaccinated and 20 negative control goats combined with 15 actively CCPP sick goats. Various clinical signs were recorded daily, autopsy was done on died goats and the live goats were sacrificed after 2 months of contact. The side by side samples from thoracic exudates, lung and mediastinal and bronchial lymph nodes were collected from goats shown to have developed indicative CCPP lesion for isolation and F38 antigen detection. The present experimental study indicated that application of inactivated and adjuvated CCPP vaccine significantly reduced the morbidity and development of lesions ( P < 0.001). Among vaccinated groups CCPP + anthrax + saponin showed better protection, with low rate of nasal discharge and cough at 33% and 28.6%, respectively, and protection level of 94.1% from death and 65% from lung lesion development. However, the variation in protection among the vaccinated groups was not significant ( P > 0.05). These findings disclosed that inactivated CCPP vaccine adjuvated with saponin and ISA 50 significantly reduce morbidity and mortality of goats due to CCPP and also indicated the importance of utilization of ISA 50 as alternative adjuvant to minimize post-vaccinal reactions encountered in use of saponin as adjuvant.

Saponin in thein vitro phosphorylation system

The possibility of the use of saponin for permeabilization of synaptic vesicles from P2 fraction is explored. This fraction is isolated from rat brain cortex. Phosphorylation of membrane-bound proteins is performedin vitro. At the saponin:protein ratio 1:10 (w/w) phosphorylation of these proteins increases 2-fold due to increased membrane permeability for ATP and cAMP. Treatment of synaptic vesicles with saponin at the same ratio leads to the loss of cytosolic but not membrane-bound protein. This concentration of saponin can be used for permeabilization of other membranes, providing that the protein:cholesterol ratio is taken into consideration.

The lipid bilayer of acetylcholine receptor clusters of cultured rat myotubes is organized into morphologically distinct domains

We have studied the composition and organization of the lipid bilayer at the large, substrate-associated clusters of acetylcholine receptors (AChR) that form in cultured rat myotubes. These clusters have a characteristic morphology consisting of alternating linear domains of AChR-rich and AChR-poor membrane, the latter involved in attaching the myotube to the substrate. We partially purified AChR clusters by extracting cultured rat myotubes with the cholesterol-specific detergent, saponin. The lipid bilayer of the cluster preparation was analyzed biochemically and the substructure of the bilayers was studied morphologically using the fluorescent probes, dansyl polymyxin B, and 3,3′-di(C 12H 25 and C 18H 37) indocarbocyanine iodide (C 12- and C 18-diI). Our results demonstrate that preparations of AChR clusters have a lipid composition biochemically similar to that of the surrounding plasma membrane. Morphologically, however, the lipid bilayer appears to be arranged into domains that resemble the interdigitating pattern seen for the AChR. This distinctive lipid organization is not due to the use of saponin to purify clusters, as we obtained similar results with clusters isolated by physically shearing myotube cultures. The domain-like organization of the bilayer at clusters is disrupted by treatments that disperse AChR clusters in intact myotubes or that remove peripheral membrane proteins from isolated clusters. This suggests that such proteins may contribute to the organization of the bilayer. Two additional factors may also contribute to the organization of the bilayer: physical constraints imposed by sites of substrate attachment and, to a lesser extent, “boundary” lipid associated with AChR.

Reevaluation, Using Marker Enzymes, of the Ability of Saponin and Ammonium Chloride to Free Plasmodium from Infected Erythrocytes

Saponin and ammonium chloride lysis have been applied for some time to the separation of erythrocyte membranes from malarial-infected erythrocytes, allowing easy isolation of the parasites. We present a reevaluation of the use of saponin and ammonium chloride as tools for isolating Plasmodium (knowlesi or falciparum) parasites. Acetylcholine esterase (EC 3.1.1.7) was used as an erythrocyte membrane marker and CDP-choline: 1,2-diacylglycerol cholinephosphotransferase (EC 2.7.8.2) as a parasite membrane marker to monitor fractionation by these agents. Both saponin and ammonium chloride produced hemolysis of uninfected and infected erythrocytes, but failed to separate host erythrocyte membrane from the parasite, regardless of its stage. Thus, saponin and ammonium chloride can be used to isolate whole infected erythrocytes, depleted of hemoglobin, by selective disruption of uninfected cells.

Derivation of Langerhans Cell Granules from Cytomembrane

OKT6 monoclonal antibody has been shown to react selectively with Langerhans cell (LC) cytomembrane in human skin. Taking advantage of this property, we examined the stainability of LC granules with OKT6 using immunoperoxidase method at the ultrastructural level. It was found that the delimiting membranes of LC granules, both attached to the cytomembrane and in the cytoplasm, were specifically stained in the epidermal sheet. These findings suggest that LC granules are derived from invagination of LC cytomembrane and retain T6 antigen. We employed two new methods: one is promotion of endocytosis by incubating the epidermal sheet in tissue culture medium with OKT6 at 4 degrees C and further incubation without OKT6 at 37 degrees C, and the other is the use of saponin to facilitate penetration of the secondary antibody through the cytomembrane of LC. In the LC cytoplasm only the delimiting membrane of the granule was stained; other membranous organelles, such as mitochondria and rough endoplasmic reticulum, did not react.

A procedure for light and electron microscopic intracellular immunolocalization of collagen and fibronectin in rat liver.

Experimental conditions have been designed that permit both extracellular and intracellular immunolocalization of various collagen types and fibronectin in rat liver. The procedure involves paraformaldehyde fixation by perfusion of the organ, use of saponin as a membrane permeabilizing agent, and visualization of the matrix components by indirect immunoperoxidase. Intracellular demonstration of collagens was particularly sensitive to the composition of the fixative and the duration of fixation. Hepatocytes contained fibronectin and types I and IV collagen, whereas fat-storing and endothelial cells evidenced type III collagen in addition. All the components were specifically located in the endoplasmic reticulum and/or the Golgi apparatus.

Entrance of cholera enterotoxin subunits into thymus cells.

Analysis of the staining of cholera enterotoxin on the surface of cells with specific antibodies against each subunit of cholera enterotoxin, using a fluorescence-activated cell sorter and electron microscopy, showed that not only subunit A but also subunit B penetrates the cell membrane. The detection of subunits inside the cell was facilitated by the use of saponin, an agent that increases membrane permeability.

Ultrastructural indirect immunolocalization of transferrin in cultured rat hepatocytes permeabilized with saponin.

Transferrin was localized in 48-hr cultured adult rat hepatocytes by indirect immunoperoxidase following paraformaldehyde--glutaraldehyde fixation and the use of saponin as a membrane permeabilizing agent. The protein, present in all the parenchymal cells in variable amounts, was found to be specifically located in the endoplasmic reticulum and Golgi apparatus. These results are consistent with recent reports claiming that all adult hepatocytes may synthesize a given liver plasma protein at a given time. The procedure used in this study should be particularly useful for the detection of intracellular antigens in various intact cell types.