TABLE 1.

hp-B6.1 consists of a heterogeneous population of cells distinguished by mutational events at particular locations within the DNA that codes for the variable region domains^a

Hybridoma/PCR clone	Nucleotide at position in Ig heavy-chain variable region domainb:
	FWR1				CDR1	FWR2	CDR2			FWR3
	7	9	16	21	103	124	153	166	178	236	237	241	269	271	297
hp-B6.1
1	A	G	G	T	G	G	A	G	G	C	C	A	T	G	C
2	A	G	G	A	A	G	A	G	G	C	T	A	T	G	A
3	A	A	G	T	G	G	A	G	G	C	T	A	T	G	A
4	C	G	C	T	G	A	A	G	G	C	T	A	T	G	A
5	C	G	C	A	A	A	A	G	G	C	T	A	T	A	A
C3.1	C	G	G	A	A	G	T	A	A	G	T	G	C	G	C
G11.2	C	G	G	T	A	G	T	A	A	G	T	G	C	G	C

^aV_H transcripts were PCR amplified and cloned, and several clones derived from each hybridoma were selected for V_H sequencing in both directions. Sequence comparisons between clones from the hp-B6.1 were compared to sequences from the C3.1 and G11.2 hybridomas. Possible point mutations from hp-B6.1 are noted by bold type. With the exception of G11.2 at position 21, C3.1 and G11.2 sequences were identical at all positions. Furthermore, the seven cloned PCR-amplified sequences from the C3.1 hybridoma were identical, and the five cloned PCR-amplified sequences from the G11.2 were identical, suggesting that, whereas the hp-B6.1 hybridoma consists of a heterogeneous cell population with respect to V_H sequences, the C3.1 and G11.2 hybridomas may each be homogeneous.

^bNucleotide positions are based on germ-line Ig alignment.