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Blood Compatibility and Plasma Compatibility – What is the Difference?

Blood Compatibility and Plasma Compatibility – What is the Difference?

To understand the compatibility, it is important that we know the bases of ABO blood grouping system. It is based on the presence of specific antigen on red blood cells of an individual.

Table 1 shows the antigens present on red blood cells and antibodies presents in plasma for each blood group.

Table 1. Antigens and Antibodies Present for Each Blood Group

Blood Group Ag Present on RBC ABO Abs Present in Plasma
O No Ag Anti A and anti B
A Ag A Anti B
B Ag B Anti A
AB Ag A and Ag B No Abs
Rh+ Rh D No Abs
Rh- No Ag No Abs

In case of Rh + or Rh– there will be no Abs present naturally in plasma because Rh Abs are developed only after an individual is exposed to Rh D antigen.

Now based on this we can differentiate the compatibility for red blood cell type and plasma type. Keep the above table as reference to understand the compatibility.

During transfusion it is preferable for a patient to receive blood and plasma of the same ABO and RhD group but if the required type is not available based on compatibility they may be given alternative type as shown in table 2.

Table 2. Blood Compatibility and Plasma Compatibility for Each Blood Group

Recipient Blood Type Donor RBC Donor Whole Blood

(RBC + Plasma)

 Donor Plasma
A+ A+, A-, O+, O- A+ A- A+, A-, AB+, AB-
A- A-, O- A- A+, A-, AB+, AB-
B+ B+, B-, O+, O- B+, B- B+, B-, AB+, AB-
B- B-, O- B- B+, B-, AB+, AB-
O+ O+, O- O+, O- A+, A-, B+, B-, O+, O-, AB+, AB-
O- O- O- A+, A-, B+, B-, O+, O-, AB+, AB-
AB+ A+, A-, B+, B-, O+, O-, AB+, AB- AB+, AB- AB+, AB-
AB- AB-, A-, B-, O- AB- AB+, AB-

When it comes to blood transfusion, it can be either only red cells or blood as a whole. So if we are talking about RBC, we need to consider only Ags from donor but when we are talking about whole blood since it has both RBC and plasma we need to consider both Ags and Abs from donor. In case of plasma we need to consider only Abs from donor because plasma doesn’t have RBC and so no Ags.

As shown in table 2, plasma from blood group AB can be given to blood group O. But when it comes to blood as a whole because of present of Ags on RBC, O type cannot accept red blood cells or blood as whole from any other blood type other than blood group O.

Blood group A and B type individuals can accept plasma from AB individuals because blood group AB type will not have any Abs in their plasma.

Blood group AB type can accept plasma from only AB type because it is the only plasma without anti A and anti B Abs in it.

Rh- individual can accept plasma from Rh+ individual because there are no anti Rh antibodies present naturally in plasma.

In blood transfusion and to be specific for red cell transfusion, AB is universal acceptor and O is universal donor.

But in plasma transfusion, AB is universal donor and O is universal acceptor.

I hope this helps 🙂

Watch a video on this topic here.

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Heterochromatin and Euchromatin – What is the Difference?

As the term says heterochromatin and euchromatin, both are different forms of chromatin. Chromatin is DNA wrapped around histone proteins. Heterochromatin and euchromatin are different levels of condensation of chromatin.

After mitosis when two daughter cells are separated, the highly condensed chromosome will return back to chromatin phase which has two outcomes. One is the loose interphase condition which is called euchromatin and around 10% remains condensed throughout the interphase which is called heterochromatin. So when we observe the nucleus we see the darkly stained heterochromatin near the nuclear envelope which is highly condensed and thus transcriptionally inactive. And in the center we observe lightly stained euchromatin which is transcriptionally active.

Euchromatin: ‘Eu’ = well. Euchromatin is less condensed form and thus it is available for transcription. Therefore, all the genes needed to be expressed are present in euchromatin region. It is gene rich.

Heterochromatin: ‘Hetero’ = different. Heterochromatin is highly condensed form and thus it is transcriptionally inactive. It is gene desert. As the term says hetero or different meaning there are two different forms of heterochromatin.

  • Constitutive Heterochromatin:

Constitutive = continuously present. That means it is the type of heterochromatin which is always or continuously in condensed form.

It remains in condensed state in all the cells at all the times. It is always transcriptionally inactive. Therefore, it represents the DNA that is permanently silenced.

It has lot of repeated sequences and has low genes (gene desert).

Examples: Centromere and Telomere

  • Facultative Heterochromatin:

Facultative = capable of but not restricted to a particular function or mode. That means it is the type of heterochromatin which can also exist in euchromatin phase.

It is specifically inactivated and it can revert back to active euchromatin phase.

It is silenced by histone deacetylation and RNAi.

Example: X-chromosome inactivation (Barr body) where one of the X-chromosome is specifically inactivated (heterochromatin phase). But during meiosis this inactivated X-chromosome need to go back to its active euchromatin stage otherwise half of the daughter cells would get inactivated X-chromosome.

Why heterochromatin is located near the nuclear envelope and euchromatin in the center?

Since the transcription is very low or not present near the nuclear envelope and heterochromatin is transcriptionally inactive we find heterochromatin near the nuclear envelope. Whereas the center of a nucleus has high levels of transcription taking place so in center we will find euchromatin because it is transcriptionally active form of chromatin.

I hope this helps 🙂

Watch a video on this topic here.