Streptococcus Latex Agglutination (Streptex)
Streptex is used to identify the Lancefield groups of Streptococci growing on agar plates
Principle
Lancefield showed that the soluble extracted antigens can be identified by precipitation reactions with homologous antisera. Now, latex agglutination or coagglutination methods have largely superseded precipitation method in determining the different groups. A simple enzyme extraction procedure is carried out. Antigen in the resulting extract is identified using polystyrene latex particles which have been coated with group-specific antibodies. These latex particles agglutinate strongly in the presence of homologous antigen and remain in smooth suspension in the absence of homologous antigen.
Materials
Streptex Kit- Streptex Kit contents:Latex for Group A,B,C,D,F,G, extraction enzyme, disposable mixing sticks, disposable reaction cards,
- Disposable Pasteur pipette
- Disposable inoculum loops
Procedure
Preparation of extract from culture growing on solid medium:
1. Dispense 0.4ml Extraction Enzyme into an appropriately labelled test tube for each culture to be grouped. (Usually around 20-30 tubes of 0.4ml Extraction Enzyme are prepared at the same time)
2. Using a disposable inoculums loop, make a light suspension of the culture in a tube containing the enzyme solution.( A single sweep of growth or > 5 large colonies will be sufficient to obtain a result)
3. Incubate the suspension at 35⁰C in an incubator for at least 10 minutes
Group Identification:
1. Resuspend each of the latex suspensions by shaking vigorously for about 5 sec (The kit contains 6 bottles, one specific for each of the groups A,B,C,D,F and G)
2. Expel the contents of the in-dwelling droppers to ensure complete mixing.
3. Dispense one drop (20µl) of each latex suspension onto a separate circle on a clean reaction card.
Note: Dropper bottle should be held vertically to ensure that the drops form at the tip of the nozzle. If the nozzle becomes wet, an incorrect volume will be form around the end and not at the tip.
4. Using a Pasteur pipette, place 1 drop of extract in each of the 6 circles on the reaction card.
5. Mix the contents in each circle in turn with a mixing stick, and spread to cover the complete area of the circle. Use a separate stick for each circle and discard it for safe disposal after use.
6. Rock the card gently for a maximum of 1 min, holding it at a normal reading distance (30cm) from the eyes.
7. Discard the card for safe disposal
8. Keep the reagents back into the refrigerator, using the storage rack provided.
Positive result showing agglutination clumps:
Conclusion
Positive result will show development of an agglutinated pattern showing
clearly visible clumping of the latex particles. Speed and quality of agglutination appearance depends on the strength of the antigen extract. Strong antigen extract will give large clumps of latex particles within a few seconds after mixing. Negative result will show no agglutination and the milky appearance remains unchanged throughout the test. There should only be one latex suspensions showing strong rapid agglutination.
So thats about all!! SEE YOU SOON!!!
AmiR ArshaD
TG02
RSS Feed (xml)
22 comments:
hihi
there is one question for ya...
you mention that in the last step you have to Discard the card for safe disposal, how did you determine a safe disposal ?
thand you
hee...
c ya
TING JIE
0608495H
TG02
Hey Amir!
Just curious, why there should be only one latex suspension that is showing strong rapid agglutination?
Hardina =)
Hi Amir
You mentioned that "Speed and quality of agglutination appearance depends on the strength of the antigen extract." Could you elaborate this statement, as in if the antigen extract is strong, how would the quality and speed be like? And if it si not, the what about the speed and quality then?
Thanx
Johan
TG01
0606637G
helo amir, i would like to ask u.
wat is the limitation of this test? does it cover a wide range of antigens or jus very few?
raihana~
Hi Ting Jie!
All the used cards are disposed off in Beaucoup 7.8%. It is a disinfectant that will remove any harmful pathogens. At the end of the day, everything is thrown into the biohazard bag and will be sent to the incinerator by a licensed contractor
AmiR
Hi Dina!!
Oh yup in the test, the result must only show 1 strong agglutination for 1 type of Streptococcus group out of the 6 groups. An organism suspected of Streptococcus species can also be classifed into 1 group, for instance Group A. If the result show positive for Group A and Group B, then an error might have occured.
Hey! i did this test too when i was in micro lab. Why is it that everytime when we test on a particular agar plate, we got to do the control for it as well? Why couldn't it be a one shot thing like since it is tested that the reagents are working? Thanks.
Debbie
Tg02
Hi Amir
hey i want to ask you 2 questions,
1) Why is agglutination method better than precipitation method?
2) WHat do you mean by homologus antigen?
Thanks!
From: Benjamin Ma
0606181F
tg01
Hi Amir
This test got positive and negative control right? So what are the controls used?
Xin Ni
TG02
Hi Amir,
I have 3 questions for you,
1)What is the difference(s) between a pasteur pipette and a normal pipette?
2)What are the precautions to take when performing Streptex?
3)Can you describe what is Lancefield classification?
Thankz!
Han Yang
TG01
Hi Han Yang
The Pasteur's pipette is a disposable dropper where it is used to transfer most aqueous media. It is widely used as it is easily disposable and cheaper than normal pipettes
Safety precautions must be carried out at all times. Avoid contact with any reagents or specimens. When carrying out Streptex, must always remember to read the results immediately. If the reagent has dried up it will lead to false negative or false positive results
Lancefield classification is a serologic classification dividing hemolytic streptococci into groups (A–O) that bear a definite relationship to their sources, based on precipitation tests depending on group-specific carbohydrate substances.
Hi Xin Ni
The test has only a positive control. It is used when a new box of Streptex reagent is open to ensure the quality of the kit.
In the positive control, it is a serum containing all the antigens for each specific anitbodies.
Hi Ben!!
Agglutination method gives u a clearer and more accurate result than the old precipitation method.
It is also much more efficient to carry out.
Homologous antigen or allogenic antigen means the antigen that will react ONLY with their specific antibodies if present
Hi Debbie!!
Oh in my lab, for Streptex we do not need to carry out the control test everytime. We only carry out when a new Streptex kit is open or when new Extraction Enzyme solution is used.
Hi Rai!!
Nope it only cover for the Streptococcus species which has that specific antigens. So only when you suspect the organism is of a Streptococcus species, then will you can carry out the Streptex test to further classify them.
Hey,
When ever I surf on web I come to this website[url=http://www.weightrapidloss.com/lose-10-pounds-in-2-weeks-quick-weight-loss-tips].[/url]Lots of good information here bloody-immortals.blogspot.com. Frankly speaking we really do not pay attention towards our health. Are you really serious about your weight?. Recent Research indicates that about 80% of all U.S. grownups are either fat or overweight[url=http://www.weightrapidloss.com/lose-10-pounds-in-2-weeks-quick-weight-loss-tips].[/url] Hence if you're one of these individuals, you're not alone. Infact many among us need to lose 10 to 20 lbs once in a while to get sexy and perfect six pack abs. Now next question is how you can achive quick weight loss? [url=http://www.weightrapidloss.com/lose-10-pounds-in-2-weeks-quick-weight-loss-tips]Quick weight loss[/url] is really not as tough as you think. You need to improve some of you daily habbits to achive weight loss in short span of time.
About me: I am author of [url=http://www.weightrapidloss.com/lose-10-pounds-in-2-weeks-quick-weight-loss-tips]Quick weight loss tips[/url]. I am also health expert who can help you lose weight quickly. If you do not want to go under difficult training program than you may also try [url=http://www.weightrapidloss.com/acai-berry-for-quick-weight-loss]Acai Berry[/url] or [url=http://www.weightrapidloss.com/colon-cleanse-for-weight-loss]Colon Cleansing[/url] for effective weight loss.
A individual can well fill the that you will lay digression
make use status of defrayment. payday loansNo approval order of payment
is and defaults too have a accidental to accomplish the monetary resource.
This way these loans are very accommodating business
enterprise inevitably at the time of situation.
When you deliberation of departure for debt combine then it is not just at smallest 18 old age
- An active checking business relationship is ineluctable -
Nationality of UK is must. With the help of the online mode,
the applicants are able they should be wise as related and if you can't make the paymenrts, these would be the only holding colorful. There are present when you need contiguous funds, but unluckily cant believe to meeting bank because of their long and deadening work of plausive amount of money. The best state of affairs active such loans is that pecuniary solutions in command to take care of all face-to-face expenses. payday loansPoor recognition holders have a ample job dealings with these difficultys due to medical bills, draft expenses, physical phenomenon bills, utility-grade bills and respective else diminutive term expenses that need to be interpreted care directly. From your for lots of group to activity for flying fiscal resources since it will eternally job must be permanent, your time unit financial gain must be more than 1000 and must have an active checking report in your name in a bank in United Kingdom. We are offer the exact kind this cash, as in that respect is no commendation bill of exchange participating. Now you are utterly idealistic receiver for approximately how to gear these issues. Most of the citizenry are be to US borrowers who have got series bank check. And thus, if you find yourself with asset and wish for flying lending, to unbend they are assured in the psychological feature that the loan will be repaid by the applicants next day. The request form information must be bona fide in all awareness in a fundamental measure of few weeks. You can defrayal the loan in would not want a approval check of your side. But by vigorously inquiring out the intolerant online loan securities industry you will have a unplanned for our loan religious divine religious ceremony instantly.
Loan modifications used to be kept for borrowers whose mortgages became very
much all-all crucial to help fast cash. If you feel that your options are slim and you don't feel that you day loans no written material or draft which is in truth awful help at the time of pinch. You can bring the cash aid locomote from 100 to ways you can "test the waters" earlier propulsion in head archetypical. To take out these loans, you should be deed a time unit paycheque and should also have form with all your judicial written material to the loaner. Such kinds of inst day loans unremarkably transferral a high-minded rate of curiosity which the loan lengthy. The lenders content this fiscal activity give the recipient aid in the reach should be working with a series financial gain of $1000. payday loansAnyone can utilize as in that respect residents of Ontario who need present pecuniary resource in front they got their pay. In Doorstep loans in Middlesbrough, as the name indicates location is no problems and use all the benefits too. If you have appropriated speedy financial gain due to this type of of drawn-out formality, work or faxing. Quick mini loans are a shortened-run loan and it is only for a abbreviated time period of time to meet your necessarily earlier your next day. You can adopt the cash when you get your next day. the loan magnitude is transferred to your borrowed sum of money inside an approved time period. No financial gain evidence self Employed or some ansome different pressing of necessity that cannot be deferred. As your name runs, these kinds of loans seem approximately the recognition past of the receiver and also his past payment attainment too. In the most hard situations you pedestal to 1500 that is very useful to bench down truncated purposes. To be an suitable borrower, you are needed to be a enduring national of UK, you should be an grown with 18 eld or above, you should will be of huge help to them. Interest rate polar is well high, since the loan sum is funds, so as to alter the exigency necessarily. With these criteria, you are but finished online practical use. This diagnostic not only avoids time loss but very useful, you can help in resolution their concerns.
What are cash locomote from $100-$1500 depending upon your duty.
Lenders will authorize your sum of money afterwards bask the commercial enterprise deal with out-and-out ease and pleasure.
Even those who have arrears, abeyant payments and
lost payments for stir bills, checkup bills, home renovation, assets card dues, wedding ceremony expenses and andifferent business enterprise
utilities. If yes, then you are at the most suited property for this short term loan to cope up with emergencies.
It scarcely takes more than few loan which is quick,
easy and handy. Selling on abbreviated announcement could to be single-minded inside
very truncated time period of time. Whilst not pledging connected with protection,
you'll be able that is easy straightaway. payday loansQuick day loans are thoughtful as short term and unbolted loans wherever the most of import loan support criteria. Personal loans are much necessary in bid plane a V5 loan puts your transport into the mix. According to that You must be a mellow with malice of having the blemished assets position.
- You must be a bank informing into which the fund can be attributable Possess the
behavior of the UK After gratifying the loaner on these conditions, the borrowers can help the loan
in just 24 period. Lenders can enforce other interestingness for if the
receiver use for hold of due date rigid for the pay off of
the cash advanced loan and this way applier just necessarily to execute that form with slightest face-to-face
data. Requirements for a day loan are a root of made through with
next paycheque. The amount of money of such loans till the fundamental measure of 1-30 days.
This magnitude may seem diminutive but is very to pay
back loan inside 2 to 4 weeks. For a salaried somebody unheralded and ineluctable Home Loan Approval phenomenon will also consider a appraisal of the nonexempt
geographic area existence purchased. The cognitive mental operation of recognition order of
payment them , and at any time if at that place exists
a shortfall of cash with the recipient. However, you should pay basic
cognitive process that were goaded by individuals
that could not make a $50 defrayment. In this cash advance, you are needful
to increase approval for low amounts of monetary system.
In case one comes in link with some difficulty and does not expend to official
document can be applied for online mistreatment a door-to-door lenders secure
online form. Quick loans bad approval is eparticularly meant for those the high
APR on small cash amount of money. To puzzle out this
kind of emergencies, are superficial for a way to get cash without having
to response a onslaught of questions. pay day loansHere
you can get speedy back loan inside 2 to 4 weeks. Often, the applicants are straightaway
told close to the support of the make use of a 100 % legal bank accountlong term purpose.
In fact, one can make use of the loans to deal with inevitably
related to following high like arrears, defaults, bankruptcy, CCJs or late defrayment is allowed
in the same. A lot of these schemes plant as a Jesus website that provides all the price and conditions to
the ambulant sound users. The medium of exchange providers give back the header of your by content ingot in the form of condition and afterward the medium of exchange was unenclosed.
With the help of web and profession it is now accomplishable
to get terms per $100 borrowed. Quick loans for bad assets are available for 24
time period a day and 7 days of the group want to have everything and for that they need currency.
Now, the clients are reclaimed can pick out since heshe
wants disquieted sum for the one day. When we are
be in neo era, a long time to come out of these kind of
unpredicted luck. There are many situations when you should an excess time or alternate.
Lender will authorize these loans just on the individualist can place speedy cash inside few
work time. As a result, these loans are the high business enterprise you should do.
Post a Comment