Nutrient media for growing gonococci. Culture medium for the isolation and cultivation of gonococcus Inoculation for gonorrhea from the eye
This agar supplemented with blood, hemoglobin or other additives is recommended for the selective isolation of gonococci.
Compound**:** The composition is verified and brought to compliance with the necessary parameters
Cooking:Suspend 7.2 g of powder in 100 ml of distilled water to prepare a double strength medium. Heat to a boil to completely dissolve the particles. Sterilize by autoclaving at 1.1 atm (121°C) for 15 min. Cool to 50°C and aseptically add separately prepared 100 ml of 2% sterile hemoglobin solution (FD022) and GC supplement (FD021). Mix thoroughly and pour into Petri dishes. To impart selective properties to the medium, you can add antibiotics included in the following additives: VNC (FD023), VCNT (FD024), Linco T (FD026), Vanco (FD028).
For the preparation of chocolate agar, a standard concentration medium is prepared by mixing 3.6 g of the powder in 100 ml of distilled water. Sterilize, add up to 5% (v/v) of sterile defibrinated blood, and heat the medium at 80°C for 10 min.
Principle and evaluation of the result:This agar supplemented with blood or hemoglobin and other additives is recommended for the selective isolation and cultivation of fastidious microorganisms such as gonococci and Haemophilus influenzae. Johnston developed chocolate agar that could grow within 24 hours. Neisseria gonorrhoeae(1). Later, other authors (2) improved the medium by introducing hemoglobin into its composition.
Agar contains a special peptone - a source of nutrients for microorganisms. Starch neutralizes toxic substances formed by Neisseria, and phosphates counteract the pH shift resulting from the formation of amines, which can also affect the growth and viability of microorganisms. Hemoglobin serves as a source of factor X for hemophilic bacteria. Another additive enriches the medium with factor V (NAD, nikoninamide adenine dinucleotide), necessary for Haemophilus influenzae, as well as amino acids, vitamins, iron ions, etc., which stimulates the growth of pathogenic neisseria.
Do not use cotton swabs to collect material. Sowing is carried out immediately after the selection of the material. It must be done so that there are zones of dense and rare growth. Seeding is incubated at 37°C in an atmosphere of 5-10% carbon dioxide and 70% humidity. All suspicious colonies should be checked in biochemical and/or serological tests.
Quality control: Powder appearance:Homogeneous free flowing light yellow powder.
Finished medium density:A medium is formed, corresponding in density to a 1.0% agar gel.
Color and transparency of the finished medium:The base of the medium is light yellow, transparent or slightly opalescent. After the addition of hemoglobin, the medium becomes chocolate brown and opaque if a gel forms in the Petri dishes.
Acidity of the environment:At 25° C., an aqueous solution (3.6% w/v) has a pH of 7.2 ± 0.2.
Cultural properties:Growth characteristics of the reference strain after 40-48 hours at 35-37°C on chocolate agar, prepared on this basis, in the presence of 5-10% carbon dioxide and 70% humidity in the atmosphere.
Laboratory methods are widely used in the diagnosis of sexually transmitted diseases of the genitourinary system: gonorrhea, syphilis, trichomoniasis, etc. The presence of the disease requires measures to identify the cause of the infection.
Nutrient medium "SVG" is intended for the isolation and cultivation of gonococci in the study of material from a patient. Each kit is designed to prepare 110 ml of gonococcal medium ready for use.
Set compositionA set for obtaining a nutrient medium should be stored at a temperature of 2 - 8 ° C for no more than 12 months. Solid nutrient medium can be stored in test tubes or Petri dishes for no more than 7 days. The set for the preparation of a nutrient medium includes:
- base: agar, yeast extract, peptone, starch, salts;
- selective additive: coenzymes, erythrocyte lysate, antifungals, antibiotics, sugars;
- instructions for using the kit.
The methodology includes several stages, each of which must be carried out in accordance with certain requirements. Upon completion of all stages of the diagnosis of the disease using the method of cultivating the pathogen on the gonococcal medium, the results are recorded after 24 hours, 48 hours and 72 hours. In acute gonorrhea, the growth of gonococcus is noted during the first day, in chronic gonorrhea - up to 72 hours.
The preparation of the base solution of the medium for cultural diagnostics is carried out by pouring the base into a container containing distilled water (100 ml) for subsequent swelling. The resulting suspension is placed in a water bath and periodically stirred until the base is completely dissolved, then the solution is boiled for 2 minutes. A solution of a selective additive is prepared by dissolving it in distilled water (10 ml) with stirring.
Ready nutrient medium is formed by adding the selective additive solution to the base solution. The resulting medium is poured into sterile Petri dishes. Before testing, the gonococcal environment must be maintained for one hour at a temperature of 37 ° C. Then the material is sown in accordance with the order of the Ministry of Health "On the unification of microbiological (bacteriological) research methods used in clinical diagnostic laboratories of medical institutions."
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Manufacturer: FBUN Research Institute of Epidemiology and Microbiology named after Pasteur
Country Russia
Unit unit: set
Packing type: cardboard box
Vendor code:
Description
A set of reagents for the isolation of gonococci by the cultural method in the study of clinical material from patients with inflammatory diseases of the genitourinary system. Designed to prepare 110 ml of solid nutrient medium, ready to use
Functional purpose
The components of the GHS kit provide optimal conditions for the growth of Neisseria gonorrhoeae to the amounts required to form visible colonies, and the selective additive inhibits the growth of protozoa, fungi and most other associated flora potentially contained in the sample.
The methodology includes several stages, each of which must be carried out in accordance with certain requirements. Upon completion of all stages of the diagnosis of the disease using the method of cultivating the pathogen on the gonococcal medium, a visual record of the results is made after 18-24 hours, 48 and 72 hours. Light gray, slightly cloudy round colonies typical of gonococci are revealed. In acute gonorrhea, the growth of gonococcus is noted during the first day, in chronic gonorrhea - up to 72 hours. The result is considered negative if there is no growth after 7 days of incubation.
Set composition
1. The basis of the nutrient medium, dry - 4.1 g x 1 bottle;
agar, yeast extract, peptone, starch, salts;
Appearance: light yellow hygroscopic powder;
2. Selective additive, lyophilized - 1 vial;
coenzymes, erythrocyte lysate, antifungals, antibiotics, sugars;
Appearance: pinkish-beige lyophilisate.
The prepared medium is clear, light yellow in color, with slight opalescence, slight sediment is allowed.
pH 7.2- 7.4
Release form: in a cardboard box along with instructions for use.
Storage conditions: at a temperature of +2...8°C for no more than 12 months, storage at a temperature of up to +25°C for no more than 2 weeks is acceptable.
Ready nutrient medium can be stored in test tubes or Petri dishes for no more than 7 days.
Registered in Roszdravnadzor
Neisseria gonorrhoeae is a member of the Neisseriaceae family, genus Neisseria. Gonococci were discovered by Neisser in 1879 and the whole family is named after him.
Morphology. Gonococci are diplococci consisting of two bean-shaped cocci lying with concave sides to each other (reminiscent of coffee beans). The size of gonococci is 1.2-1.3 × 0.7-0.8 μm. They are polymorphic; along with large ones, there are very small, irregularly shaped L-shaped bacteria. Gonococci are immobile and do not have spores. A capsule-like substance is found in the pathological material (pus). Gram-negative. Under the influence of medicinal and other substances, they quickly change: gram-positive forms appear. In the pathological material, they are located intracellularly (in a leukocyte), but may be outside the cell. May be in the form of individual cocci (see Fig. 4).
Cultivation. Gonococci are aerobes. Very demanding on nutrient media. They grow on media containing native protein (human) - blood, serum, at a temperature of 37 ° C and a pH of 7.2-7.4. Media should be freshly prepared and moist. Sowing should be done immediately after taking the material. On serum medium, gonococci form small colonies 1-2 mm, transparent, shiny with smooth edges, resembling dew drops. On the blood medium, hemolysis is not given. In whey broth, they give a slight turbidity and a film that settles to the bottom of the tube. With poor growth after 24 hours, the crops are left in a thermostat for the second day.
enzymatic properties. Saccharolytic properties are weakly expressed. Gonococci break down only one sugar - glucose with the formation of acid. They do not have proteolytic properties.
Toxin formation. In the cell wall of gonococci there is a toxic substance - lipopolysaccharide (little studied).
Antigenic structure. The antigenic structure is heterogeneous and easily changes under the influence of environmental factors. There is no generally accepted division of gonococci into serovars and serotypes yet.
Resistance to environmental factors. In the external environment, gonococci are not very stable. At a temperature of 56-60 ° C, they die. At a temperature of 40 ° C, their viability decreases sharply. Low temperatures and drying quickly destroy them. But in pus they remain up to 24 hours. Disinfectant solutions - 1% solution of phenol, sublimate 1:1000 kill gonococci within a few minutes. Gonococci are especially sensitive to silver salts - a 1% solution of silver nitrate destroys them immediately. UV rays kill them within minutes.
Susceptibility of animals. Animals are not susceptible to gonococcus. However, intraperitoneal administration of gonococcal toxin to white mice causes their death.
Sources of infection. A person with gonorrhea.
transmission paths. Contact-household (sexual), less often through contaminated objects (towel, sponges, etc.).
Diseases in humans. Gonorrhea and blennorrhea.
Pathogenesis. The natural host of gonococci is a sick person. Gonococci penetrate through the mucous membranes of the urethra (in women - the urethra and cervix). The pathogenicity factor of gonococci is the presence of pili in them, which, connecting with the microvilli of the cylindrical epithelium, contribute to the penetration of the gonococcus into the epithelial cell, causing an acute inflammatory process in the mucous membrane.
Clinically, gonorrhea is manifested by pain during urination, discharge of pus from the urethra and vagina. The disease is acute, but sometimes becomes chronic. Gonococci can cause gonorrheal conjunctivitis - blennorrhea (purulent inflammation of the mucous membrane of the eyes in newborns). Gonococci rarely spread from the urethra to other organs, but sometimes they can cause arthritis, endocarditis, etc.
Immunity. There is no natural resistance to gonococci. The transferred disease also does not create immunity. The observed phagocytosis is incomplete.
Prevention. Health education. Increasing the cultural and hygienic level. There is no specific prevention. For the prevention of blennorrhea, children immediately after birth must be injected into the conjunctival sac 1-2 drops of a 30% solution of albucid.
Treatment . Antibiotics (penicillin, bicillin, streptomycin, etc.). Sulfa drugs are also used. In the chronic form, a gonococcal vaccine is used.
Control questions1. Describe the morphological properties of gonococci.
2. What are the enzymatic activity and toxin formation of gonococci?
3. What is the resistance of gonococci. To what drug are gonococci particularly sensitive?
4. What diseases are caused by gonococci and their pathogenesis.
Microbiological researchThe purpose of the study: detection of gonococci and anti-gonococcal antibodies.
Research material
1. Detachable mucous membrane of the urethra in men.
2. Discharge of the mucous membrane of the urethra and cervix in women.
3. Purulent discharge from the eyes.
4. Blood to obtain serum.
Note. For bacterioscopic and bacteriological examination, the material is taken: 1) before the start of antibiotic treatment: 2) not earlier than 10 days after the end of antibiotic treatment; 3) not earlier than 2 hours after the last urination; 4) not earlier than 2 hours after douching.
Basic research methods
1. Microscopic (mainly used in acute forms).
2. Microbiological.
3. Serological.
Research progress
Second day of research
Take out the crops from the thermostat and view them. Studying the colonies. They make smears. In the presence of suspicious gram-negative diplococci, the colonies are subcultured on a slant medium in test tubes (the medium must be freshly prepared and contain a sufficient amount of condensate) and a sample is taken for oxidase. To do this, a drop of 1% dimethyl paraphenylenediamine solution is applied to the colony with a pipette, the colonies change color from dark brown to black.
Third day of research
The cultures are taken out of the thermostat, swabs are taken from the agar slant, stained by Gram and microscoped. Inoculated on Hiss media (lactose, glucose, mannitol and maltose). These carbohydrates should contain 30% of blood serum. The inoculated tubes are placed in a thermostat.
Fourth day of research
Remove the test tubes from the thermostat, in the absence of growth, leave them in the thermostat for another 1-2 days. In the presence of growth, the results are taken into account (Table 28).
Serological diagnosis
third week of illness. In the chronic course of the disease and in doubtful cases, RSK is placed with the patient's serum (see Chapter 12). As an antigen, a killed culture of gonococci, which is prepared under industrial conditions, is used. You can apply the reaction of indirect hemagglutination (see Chapter 12).
Control questions
1. What material is used to detect gonococci and how is it obtained?
2. How long after urination (or douching in women) can material be taken for research?
3. What research method is the main one for acute gonorrhea and what method for chronic gonorrhea?
4. When and what kind of serological reaction is given for suspected gonorrhea?
5. From what microorganisms it is necessary to differentiate gonococci?
Get the drug from the teacher. Examine it and draw the gonococci located inside and outside the leukocyte on a Gram stain.
Nutrient media
Yolk environment. To 100 ml of MPA from rabbit meat add 15 ml of yolk (fresh chicken egg), 6 ml of phenol red indicator, 1.5 ml of sugar dissolved in 1 ml of sterile distilled water.
Nutrient medium ascites-agar. 2% agar, 1% peptone and 0.5% sodium chloride are added to the filtrate of the broth prepared from rabbit meat. Heat until the agar dissolves, set the pH to 7.4-7.5, alkalinize with 20% sodium hydroxide. The medium is brought to a boil, filtered, poured into sterile vials and sterilized in an autoclave for 15 minutes at 115°C.
Recipes for ascitic nutrient media (MPA pH 7.4-7.5).
1) meat water from rabbit meat or bull hearts - 100 ml
casein hydrolyzate - 2 ml
yeast autolysate - 2 ml
blood serum of cattle - 20 ml
2) meat water from rabbit meat or bull hearts - 100 ml
5% solution of hemohydrolyzate - 2 ml
yeast autolysate - 2 ml
bovine serum - 20 ml
3) meat water from rabbit meat or bull hearts - 100 ml
chicken egg yolk - 10 ml
blood serum of cattle - 20 ml
The growth of gonococci on these media is abundant. Gonococcus colonies can be detected by an oxidase test, which turns red to black.
The effectiveness of the bacteriological research method in
largely determined by the quality of nutrient media. IN
In our country, two types are most widely tested and used
nutrient media: ascites-agar and non-ascitic nutrient media.
Both media are based on meat-pentone agar (MPA) from meat
rabbits or fresh bovine hearts. The method of its preparation
is as follows. Rabbit meat is freed from fat and
tendons, passed through a meat grinder or chopped with a knife,
weighed, filled with double the volume of tap water and in this
the form is left in the refrigerator at 4° for a day for extraction.
Then the mass is heated to a boil, boiled for 10 minutes, cooled and
filtered through cheesecloth. To the filtrate add 2% agar-agar, 1%
peptone and 0.5% sodium chloride, heated until the agar-agar dissolves
and set pH = 7.5-7.6 (alkalinization is carried out by 20%
sodium hydroxide solution). The medium is brought to a boil, filtered
through a cotton-gauze filter, pour into sterile vials or
flasks and sterilized in an autoclave for 15-20 minutes at 0.5 atmospheres
pressure gauge (112ё).
The technique for preparing MPA from fresh bovine hearts is the same as
only boiling a mass of crushed hearts in water follows
produce 20 minutes instead of 10.
It is possible to prepare the basis of the nutrient medium without peptone.
In this case, the above method for preparing MPA is used, but
peptone is excluded from its composition, chopped rabbit meat is boiled
5 minutes instead of 10 and sterilize the medium in an autoclave for 10
minutes at 0.8 atmospheres on a pressure gauge (117ё).
Ascites agar
Ascitic fluid should be obtained from patients with
ascites due to heart failure, and
produced through the trocar into a sterile bottle and add 5% to it
chloroform for anesthesia. For 10 days, the liquid is mixed with
chloroform by rotating the bottle, then leave it at
room temperature until the chloroform completely settles to the bottom of the bottle
and clarification of the liquid. After that, as needed, transparent
ascitic fluid is poured into 50 ml sterile flasks with
cotton plugs and daily for 3 days they are placed in
water bath at 56 ° for 1 hour to evaporate chloroform
through a cotton plug. After checking the ascitic fluid for
sterility it can be used for enrichment
nutrient medium for the isolation of gonococcus at a concentration of 1/3 and 1/4
the volume of the medium, which is determined empirically.
Ascitic Media Recipes
1. MPA from rabbit meat or fresh bovine hearts
(рН=7.4-7.5) - 100 ml, casein hydrolyzate for parenteral
protein nutrition - 2 ml, yeast autolysate - 2 ml, whey
blood of cattle - 20 ml (Wednesday KDS-1).
2. MPA from rabbit meat or fresh bovine hearts
(рН=7.4-7.5) - 100 ml, 5% hemohydrolyzate solution - 2 ml,
yeast autolysate - 2 ml, bovine blood serum
cattle - 20 ml (GDS-2 medium).
3. MPA from rabbit meat or fresh bovine hearts
(рН=7.4-7.5) - 100 ml, medium 199 for tissue cultures without
antibiotics - 20 ml, yeast autolysate - 2 ml, blood serum
cattle - 20 ml (medium 199-SDS).
4. MPA from rabbit meat or fresh bovine hearts
(рН=7.4-7.5) - 100 ml, fresh chicken egg yolk - 10 ml,
blood serum of cattle - 20 ml (Wednesday ZhS).
Egg yolk is obtained sterile from dietary chicken eggs.
immediately prior to medium preparation. For this,
pre-treated with alcohol, the shell is opened with a sterile
with tweezers and the contents of the egg are poured into a sterile funnel. After
after the protein flows out, the yolk remaining in the funnel is transferred to
sterile dishes and a measuring pipette are taken necessary for
production of the nutrient medium volume of the yolk.
Preparation of yeast autolysate is as follows.
Baker's yeast is crushed and placed in a bottle exceeding
volume taken yeast 4 - 5 times, and leave for autolysis for two
days in a drying cabinet or thermostat at 60 °. Then thick
brown mass is diluted with a triple volume of warm tap water
water, mix well and centrifuge twice for 10 minutes at
1000 rpm (until the liquid becomes clear). supernatant
the liquid is drained, 0.5% sodium chloride is added to it, adjusted
pH to 7.4-7.5 and autoclaved for 30 minutes at 1 atmosphere for
manometer (120ё). Store in small containers in the refrigerator
Yeast autolysate can be replaced with a 1.5% solution
fodder yeast extract (EKD) in the same amount (2 ml) 1.5%
EPC solution is prepared in the laboratory from dry EPC by dissolving it in
sterile distilled water. Prepared this way
liquid extract is poured into sterile test tubes and sterilized in
autoclave at 0.5 barg for 20 minutes.
In all the above nutrient media, blood serum
cattle can be replaced by normal native
serum for bacteriological nutrient media, which
is the same serum, but with the addition of a preservative.
Preparation of the enriched medium
MPA, located in a vial or flask, is melted in water
bath, cooled to 56-58ё and add ingredients to it in
ratios indicated earlier in the recipes. Enriched with MPA at 3-3.5
ml is poured into sterile test tubes, the medium is slanted and moistened
0.5 ml sterile meat-peptone broth or isotonic
sodium chloride solution after it hardens. For check
for sterility, the medium is placed in a thermostat at 35-37o per day.
All of the above non-ascitic media, except egg, are transparent,
it is easy to differentiate colonies of microorganisms on them. Wednesday,
enriched with egg, differs in turbidity, it is yellow, grown on
her colonies, in particular, gonococci, are poorly distinguishable. However, growth
gonococcus is abundant on this medium and its colonies can easily be
detected by growth treatment with 1% solution
dimethyl paraphenylenediamine or other oxidase reagent,
which stains gonococcus colonies red, well
contrasting against the yellow background of the medium. The use of yolk
media without microbial growth treatment with an oxidase reagent
The quality of each new batch of laboratory culture medium
production must be checked by sowing on it
pathological material from patients in whom bacterioscopically
gonococci were found.
The shelf life of MPA in a refrigerator at 4o should not exceed 1
month, enriched environment - 7 days.
Due to the fact that for the above environment a short period of time is possible
storage, developed a method of manufacturing
lyophilized ascite-free nutrient medium, which is under
titled "Gonococcal isolation culture medium, dry"
available in two bottles: part I (medium base) and part II
(fortifiers). To prepare the working environment in part I
add 100 ml of sterile distilled water and heat
in a water bath at 100 ° until the contents of the vial are completely dissolved
(within 30 minutes). Extra time to withstand the environment in water
bath should not be, tk. this reduces its quality. Part II includes
24 ml sterile distilled water (dissolving enriching
substances occurs immediately). Then, subject to the conditions
sterility, part II is transferred to part I cooled to 56°,
mixed, poured into sterile test tubes, beveled and
moisturize as previously described.
Dry medium is prepared from rabbit meat or bull hearts,
in addition to those listed in recipe 1 (KDS-1 medium) enriching substances
it contains orotic acid at a concentration of 1 µg/ml. Wednesday
high quality, convenient for use in bacteriological
laboratories, because to convert a dry environment into a working one, it is required
only sterile distilled water.
The use of ascite-free nutrient medium with the addition
antibiotics and orotic acid gives good results with
bacteriological diagnostics, including extragenital
gonorrhea: gonorrhea of the tonsils and pharynx, rectum. Antibiotics
added to inhibit the growth of concomitant gonococcus
bacterial flora, which increases the growth rate of gonococcus,
facilitates the detection of its single colonies and isolation in pure
culture. Add 20.0 U/ml polymyxin M sulfate and 6.2 U/ml
ristomycin sulfate; instead of the latter, you can use
lincomycin hydrochloride - 2 μg / ml. Orotic acid is injected into
the composition of the nutrient medium in the amount of 1 µg/ml.
To do this, take a sample of orotic acid 1 mg (1000 μg) and
diluted in 1.0 ml of sterile distilled water (obtain
working solution containing 1000 mcg which can be stored in
refrigerator for 10 days) and sterilized in a water bath 15
minutes, then take 0.1 ml of the resulting solution and add to
100 ml enriched nutrient medium. Environment with antibiotics
must be used simultaneously with antibiotic-free medium
(one test tube with the medium with antibiotics, the other without them), because
although rare, there are strains of gonococcus that are sensitive to
the above antibiotics.
Storage medium (transport)
Composition of the preservation medium: 1) 1 liter of distilled water,
free from chlorine, 30 g of agar-agar; 2) 900 ml distilled
chlorine-free water, 2 ml thioglycolic acid, 12 ml 1M
sodium hydroxide solution, 100 ml of 20% aqueous sodium solution
monosubstituted phosphate, 20 ml of 1% chloride solution
calcium. The last mixture (2) is added to the freshly prepared
agar (1), adjust the pH to 7.3-7.4, pour 10 ml of the medium into
sterile test tubes, sterilized with flowing steam for 1 hour.
Cotton swabs on wooden sticks or rods made of
stainless steel with a diameter of about 2 mm, mounted in wadded
stoppers, boiled for 20 minutes in phosphate buffer, pH=7.4, and
impregnate for 24 hours in a 1% aqueous suspension finely
crushed charcoal. After drying, cotton swabs
correct, insert into bacteriological test tubes
of the appropriate diameter (equal to the diameter of the test tubes with the medium) and
sterilized in an autoclave for 20 minutes at 1 atmosphere (temperature
To prepare phosphate buffer, two solutions are prepared: 1
solution - 28.4 g of sodium are dissolved in 1 liter of distilled water
disubstituted phosphate (0.2M); 2 solution - in 1 l
distilled water dissolve 27.8 g of citric acid (0.1 M).
Mix 181.7 ml of solution 1 and 18.3 ml of solution 2.
Seeding production using the save environment
is carried out as follows. Doctor examining a patient
removes a tampon from the test tube, introduces it into the focus of the disease on
a few seconds for soaking (you can do several
movements clockwise and counterclockwise), removes it without touching
surrounding objects, into a test tube with preservation medium. over
cotton plug, the test tube is closed with a rubber nipple. Before shipping
material to the bacteriological laboratory, the cultures are kept at 4
in the refrigerator for a minimum period, but no more than a day. Simultaneously
take pathological material and make smears for
bacterioscopic examination, which are sent to
laboratory along with culture. in bacteriological laboratory
immediately after receipt swabs with pathological material
removed from the storage medium and they are used to inoculate on the surface
slanted nutrient medium in test tubes. Each tampon is made
sowing on a nutrient medium in two test tubes. Seeding on the surface
nutrient medium should be made in zigzag movements
along the surface of the medium by rotating the swab. If the diameter of the test tubes
the preservation medium and growth medium is similar, you can swab
after inoculation, leave in the second test tube in contact with
nutrient medium. Crops are placed in a thermostat and grown at
36-37yo in a desiccator. It should be borne in mind that when using
preservation environment, the growth of gonococcus may occur later than with
direct sowing of pathological material on nutrient
Working with cultures
Gonococci can be grown in test tubes or
Petri dishes; The first method provides significant savings
environment. To increase the percentage of seeding of gonococci, seeded
nutrient media are placed in a thermostat in a desiccator with 20%
reactions between sulfuric acid and sodium bicarbonate: into a desiccator
with a volume of 5 liters, place a glass with 50 ml of 10% sulfuric acid, in