LBC Flashcards
(42 cards)
What are the 2 LBC systems?
SurePath and ThinPrep.
What have been the main benefits of LBC?
LBC has reduced inadequate samples. LBC make effective collection of sample easier.
What fixative does SurePath use?
SurePath uses a 24% ethanol fixative.
What vials does SurePath use?
10ml vials of 13mm diameter.
Does the SurePath system require separate staining?
No, the SurePath system uses a batch processor with integrated staining.
True or false? The SurePath system requires additional pre processing steps for blood stained samples.
False. No preprocessing steps are required for blood stained samples.
What process produces slides in the SurePath system?
Slides are produced using a unique cell enrichment process and centrifugation.
What vials are used in ThinPrep?
20ml vials of 22mm diameter.
Is the brush head retained in the vial for the SurePath method?
Yes.
Are the brush heads retained in the vile for ThinPrep?
No. Brush heads are rinsed into the vial.
Is there any form of integral staining included in the ThinPrep method?
There is no integral staining in ThinPrep.
How would you deal with blood stained samples before using the ThinPrep method of LBC?
Pre-processing steps are required for blood stained samples when using ThinPrep.
What basic methodology of slide preparation does ThinPrep utilise?
Filtration methodology.
What are the benefits of the SurePath sample collection method compared to previous methods?
100% of the material is sent to the lab. No abnormal cells are discarded. Ethanol fixative ensures endocervical cells do not adhere to the brush head.
A standardised sampling method is used which provides easy of use for sample takers and is comfortable for the patient.
What is the cervical sampling device called?
The Rovers Cervix Brush.
How does one take a cervical sample for SurePath LBC?
The Rovers cervical brush is inserted into the cervical internal OS and rotated in a clockwise direction whilst pushing towards the cervix.
The lateral bristles will splay out over the extocervix and the central bristles will penetrate the endocervical canal.
Five full rotations are completed and then the broom head is popped off into the SurePath vials. It is important that the brush is rotated in the right direction as the bristles are D shaped and must be twisted clockwise to sample correctly.
It is important that the endocervical canal is sampled to ensure that the area where the changes take place ( the transformation zone) is sampled.
Who can Rovers brush be used on?
All patients and up to 10 weeks gestation.
What often cause conventional smears to be inadequate?
Too scanty, Too thick, Poor fixation, Endocervical cells only, Obscured by polymorphs, Catalysed, Obscured by RBCs, Obscured by bacteria.
The SurePath preparation process has two main stages, what are they?
1) . Enrichment
2) . Auto slide production and staining
Describe the process of SurePath sample preparation.
All samples are labelled at the start of the process ensuring secure quality assurance checking procedure. The same standardised procedure is used for all samples.
1) . Vials are vortexed.
2) . A PrepMate machine is used to homogenise the sample. It does this using a syringing action and then removes an aliquot from the sample and transfers it to a density gradient tube.
3) . Enrichment via centrifugation then takes place. The sample is spun down and the supernatant is aspirated off. This is then repeated leaving a cell pellet. All excess blood and inflammatory material is now removed. Without enrichment you would get incomplete cell coverage.
4) . PrepStain then takes place. Up to 48 slides can be stained per hour. It is a semi automated walk away process. There will be standardised staining within each lab. It reduces cross contamination, requires no filtration and has non gynae applications.
SurePath also allows you to make additional slides and also produce unstained slides for ICC.
How are ThinPrep slides stained?
They are taken of the machine and stained in the traditional manner.
Describe the slides produced using SurePath.
SurePath produces a thin layer homogenous slide with 50-70k cells per slide.
Obscuring blood and 50% of inflammatory material is removed while retaining diagnostic clues in the background.
Diathesis will not be removed if present.
Small (13mm) diameter.
There is a facility to make proportional matched copies.
Excellent nuclear details with crisp membranes.
Can incorporate standardised bespoke staining if required.
What is the benefit of the SurePath enrichment process?
It removes obscuring blood and 50% of inflammatory material while retaining the diagnostic clues in the background.
The unique enrichment process ensures the slide produced is reflective of the sample taken.
In what way does SurePath enable individual performance of sample takers to be monitored?
Because the brush head is retained in the vial and the complete specimen is sent to the laboratory this what is collected from the cervix is demonstrated on the slide.
The process is not dependent on the precision of the sample taker to remove material from the sampling device.