MLS 308 Blood Grouping Techniques

Comprehensive vocabulary flashcards covering principles, methods, and result interpretations for blood grouping as detailed in the MLS 308 lecture notes.

Blood grouping

A laboratory process used to determine an individual’s blood group, particularly the ABO and Rh systems, focusing on antigen–antibody interactions.

Forward Grouping (Antigen Detection)

A process where red cells are tested against known antisera (Anti-A, Anti-B, Anti-D) to detect the presence of corresponding antigens.

Reverse Grouping (Antibody Detection)

A process where plasma or serum is tested against known red blood cells (A cells, B cells) to detect naturally occurring antibodies like anti-A or anti-B.

Agglutination

The visible clumping of red blood cells that occurs when a corresponding antigen and antibody meet.

Slide Method

A rapid screening method where one drop of blood is mixed with known antisera (Anti-A, B, D) on a slide to observe clumping within $1-2\,\text{minutes}$.

Tile Method

A simple and inexpensive technique using a ceramic tile or glass slide to detect ABO and Rh antigens, commonly used in emergency settings or small-scale blood banks.

Tube Method

A sensitive standard method for routine blood bank analysis where agglutination is enhanced by centrifugation; it can be performed via Spin tube or Sedimentation methods.

Autoagglutination control

A mandatory control in the tube method consisting of patient serum tested against patient red cells.

Tube Method Centrifugation Parameters

The process requires centrifuging the mixture at $200\text{g}$ for $1\,\text{minute}$ after a $30\,\text{minute}$ incubation period.

Microcolumn or Gel Agglutination Technique

A modern method using centrifugal force to pass blood cells through a gel-filled card; clumped cells are trapped at the top while non-agglutinated cells form a pellet at the bottom.

Microplate technique

A high-throughput method using injection molded polystyrene plates containing $96$ wells ($8$ rows vertically by $12$ rows horizontally) to process multiple samples simultaneously.

Microplate Positive Result

Observed as a smooth, uniform blanket of cells at the bottom of the well.

Microplate Negative Result

Observed as a compact, distinct "button" of cells at the bottom of the well.

Automatic Reader Wavelength

The specific wavelength used to read microplate results, which is $570\,\text{nm}$.

Weak D

A variation of the D antigen that cannot be reliably detected by the slide or tile methods and requires more sensitive techniques like the Gel Agglutination Technique.